Effect of Lifestyle Modification and Metformin on Fetuin-A and

Transforming Growth Factor-ß (TGF- ß) in Metabolic Syndrome

Melati Silvanni Nasution

, Dharma Lindarto

Department of Internal Medicine, Faculty of Medicine, Universitas Sumatera Utara,

H. Adam Malik Hospital, JalanBunga Lau No 17, Medan 20136, Indonesia.

Keywords: Metabolic syndrome, lifestyle modification, fetuin-A, TGF- ß

Abstract: Fetuin-A is a liver-synthesized protein that is secreted into the serum. Transforming growth factor-β (TGF-

β) is a polypeptide member of the TGF-β superfamily of cytokines. The purpose of this study is to evaluate

the effects of lifestyle modification and metformin on fetuin-A and Transforming Growth Factor-ß (TGF- ß)

in metabolic syndrome (MetS). Forty MetS subjects were randomly assigned to treatment with placebo

(n=20) or metformin (n=20) in addition to lifestyle modification for 12 weeks. All 40 participants completed

the study. After 12 weeks, both groups had significant reductions in weight, body mass index (BMI), waist

circumference (WC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) (all p<0.001). The

placebo group also had significant improvement in fasting plasma glucose (FPG) and C-reactive protein

(CRP) (p<0,001 ; p<0.05 respectively). Weight, BMI, WC, FPG, 2-hour postprandial glucose (2h-PPG),

high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), fetuin-A and TGF- ß in the metformin

group decreased significantly compared to the placebo group. Reduction of plasma fetuin-A was

significantly associated with TG in the metformin group. Lifestyle modification and treatment with

metformin for 12 weeks improved cardio-metabolic risk factors in Mets and reduced fetuin-A levels.

1 INTRODUCTION

The Metabolic Syndrome (MetS) represents a

combination of cardio-metabolic risk factor

determinants including central adiposity, insulin

resistance, glucose intolerance, dyslipidemia, non-

alcoholic fatty liver disease (NAFLD) and

hypertension. It is rapidly increasing in prevalence

worldwide as a consequence of the obesity

epidemic. As a result, the Mets will have a

considerable impact on the global incidence of

cardiovascular disease and type 2 diabetes (T2DM)

(Bruce et al., 2009). Insulin resistance is thought to

be the primary underlying abnormality leading to

Mets (Reaven, 1988).

Fetuin-A (also known as human protein alpha-2-

Heremans-Schmid-glycoprotein, AHSG) and other

circulating proteins have been shown to be involved

in the regulation of insulin sensitivity. Fetuin-A is a

liver-synthesized protein that is secreted into the

serum. It can bind the insulin receptor and inhibit

insulin signaling in skeletal muscle and hepatocytes,

inhibiting insulin signal transduction and resulting in

insulin resistance in the target tissues (Srinivas et al.,

1993). In humans, higher levels of fetuin-A are

associated with higher TG, low-density lipoprotein

cholesterol (LDL-C), BMI, and insulin resistance

(Stefan et al., 2006). Higher fetuin-A concentrations

were associated with the accumulation of visceral

adipose tissue, a major component of the Mets (Ix et

al., 2009). The link between fetuin-A, obesity,

insulin resistance, NAFLD, and Mets in humans is

less clear. Some studies in adults have reported

significant associations between fetuin-A, NAFLD

and insulin resistance (Mori et al., 2006). Most of

these studies were cross-sectional and limited by

many confounders. Longitudinal studies are

preferable to clarify these metabolic relationships.

Transforming growth factor-β (TGF-β) is a

polypeptide member of the TGF-β superfamily of

cytokines. The TGF-β superfamily consists of TGF-

β, activins, inhibins, growth differentiation factors,

and bone morphogenetic proteins (BMPs). The

TGF-β superfamily proteins share common

sequences and motifs to exert their various

biological actions, including cell growth,

differentiation, proliferation, migration, adhesion,

Nasution, M. and Lindarto, D.

Effect of Lifestyle Modiﬁcation and Metformin on Fetuin-A and Transforming Growth Factor-ß (TGF- ß) in Metabolic Syndrome.

DOI: 10.5220/0010018704650472

In Proceedings of the 2nd International Conference on Tropical Medicine and Infectious Disease (ICTROMI 2019), pages 465-472

ISBN: 978-989-758-469-5

465

apoptosis, and extracellular matrix (ECM)

production. Metabolic syndrome is mostly

characterized as visceral fat obesity with multiple

cardiovascular risk factors, including elevated blood

pressure, hyperglycemia, and dyslipidemia.

Therefore, an understanding of the molecular

mechanism by which visceral obesity is promoted is

essential for preventing cardiovascular events in

individuals with MetS (Ken-ichiet al., 2011).

Lifestyle modifications (LSM) to address

overweight, physical inactivity and an atherogenic

diet have been recommended as a foundation for the

management ofMetS(Eckel et al., 2005). However,

LSM alone is often unable to achieve clinically

meaningful weight loss (UKPDS, 1998).

Metformin, a biguanide oral antidiabetic agent,

has been shown to reduce weight, hyperinsulinemia,

and hyperglycemia in adult patients with T2D. It is

recommended as first-line pharmacotherapy in

overweight and obese T2D patients (Shroff et al.,

2010). While metformin has been found to attenuate

the insulin-sensitizing effect of exercise, it has been

found to have beneficial effects on inhibition of

platelet aggregation, antioxidant activity, weight

reduction, lipid parameters (total cholesterol, HDL-

C, LDL-C and TG) and arterial hypertension

(Glueck et al., 2001, Wulffeléet al., 2004, Pasquali

et al., 2000). Metformin can be given safely to

euglycemic patients, as it does not induce

hypoglycemia (Linet al., 2000). Furthermore, in

ob/ob mice, a model of hepatic steatosis, metformin

reversed hepatomegaly, hepatic fat accumulation,

and ALT abnormalities by reducing hepatic tumor

necrosis factor-α (TNF-α) expression (WHO, 2004).

The aim of this study was to assess the effect of

LSM on cardio-metabolic risk factors, fetuin-A and

TGf-ß levels with or without metformin in relation

to the improvement of insulin sensitivity in patients

with the Mets.

2 MATERIALS AND METHODS

Study subjects who met the 2006 IDF definition of

the metabolic syndrome were recruited from the

nurse of H. Adam Malik Hospital in Medan,

Indonesia. The criteria included central obesity (WC

of ≥ 90 cm in men and ≥ 80 cm in women of Asian

ethnicity) plus any 2 of the following 4 factors:

elevated triglycerides (≥ 150 mg/dL) or specific

treatment for this lipid abnormality, reduced HDL-C

(< 40 mg/dL in men and < 50 mg/dL in women) or

specific treatment for this lipid abnormality, elevated

BP blood pressure (SBP ≥130 mmHg or DBP ≥ 85

mmHg) or treatment of previously diagnosed

hypertension, and elevated FPG (≥ 100 mg/dL) or

previously diagnosed type 2 diabetes (WHO, 2004,

IDF, 2006). Exclusion criteria included smoking,

known cardiovascular disease or any major illness,

and use of medication that could affect laboratory

test results. Forty subjects gave their full informed

consent to participate and undergo LSM for 12

weeks. They were assigned randomly to treatment

with either placebo or metformin.

Each participant was advised to take one capsule

three times a day after meal. For the placebo group,

the capsule contained calcium gluconate 500 mg.

For the metformin group, the capsule contained

metformin 500 mg. No vitamins or other nutritional

supplements were prescribed. Prior to initiation and

during the study, all the participants discussed LSM

including diet and physical activity with a trained

health nurse. To facilitate behavior change, each

participant received an instructional leaflet and a

diary to record behavioral performance, diet,

physical activity, WC and weight. Every week, all

participants attended a follow-up meeting for

confirmation of compliance and monitoring of any

health and safety problems related to behavioral

changes and treatment.

2.1 Anthropometric and Body

Composition Measurements

Baseline anthropometric measures were taken. The

following BMI categories appropriate for Asians

were used: underweight, BMI < 18.5 kg/m

; normal,

18.5 to 22.9 kg/m

; overweight, 23.0 to 24.9 kg/m

;

obese class I, 25.0 to 29.9 kg/m

; obese class II BMI

≥ 30.0 kg/m

(Misra et al., 2007). BMI was

measured every week to assess the immediate effect

of LSM.

2.2 Diet and Exercise Regimen

For 12 weeks, all subjects followed a weight

maintenance diet (total calories per day divided into

55 to 60% carbohydrate, 15 to 20% protein and 20 to

25% fat) and moderate exercise in accordance with

recommendations from the Endocrinology

Association of Indonesia (Perkeni, 2011). All

subjects were free-living and consumed self-selected

foods from a list of food replacements made

according to their individual dietary habits. The

dietitian reviewed the participants' diet on a weekly

basis to ensure compliance.

The exercise program consisted of moderate

aerobic exercise at least 3 times per week, with a

ICTROMI 2019 - The 2nd International Conference on Tropical Medicine and Infectious Disease

466

minimum of 30 minutes for each session (Perkeni,

2011). Each session included 5 minutes of warm-up,

20 minutes of main exercises, and 5 minutes of

relaxation exercises. Each training session was

supervised by a physiotherapist.

2.3 Blood Pressure and Blood Sample

Analysis

Blood pressure was averaged from two

measurements using a mercurial

sphygmomanometer after a 10-minute rest. All

subjects reported for blood sampling in the morning

after an overnight fast. Blood samples were

centrifuged for 15 minutes, after which plasma- and

serum-containing tubes were stored at -20

C until

analysis. Blood glucose was measured by

photometer autoanalyzer Modular P800. Plasma

HDL-C, LDL-C, and TG were measured using

ARCHITECT ci8200 (Abbott Diagnostics, USA).

High-sensitivity CRP was measured by sensitive

immunoassay using Immulite® 1000 Analyzer

System (Siemens Healthcare, Germany). HbA1c

measurement was done by high-performance liquid

chromatography (HPLC) using D-10™ (Bio-Rad,

USA). Homeostatic model assessment of insulin

resistance (HOMA-IR) was computed using the

formula:

HOMA-IR = FPG x fasting serum insulin / 22.5

where FPG is expressed in mmol/L and fasting

serum insulin in mU/L. Fetuin-A determination was

performed by human fetuin-A enzyme immunoassay

and TGF-ß also by enzyme immunoassay

2.4 Statistical Analysis

Data were presented as mean ± SD. The normality

assumption of data from the placebo group and the

metformin group was evaluated and confirmed using

the Shapiro-Wilk normality test. Differences

between and within groups were tested using the

dependent t-test and independent sample t-test.

Abnormal data were tested using the Mann-Whitney

U test, Wilcoxon test, and Spearman's correlation

coefficient test. Two-sided p-values of less than 0.05

were regarded as statistically significant. The data

were analyzed using SPSS software.

The local Ethics Committee approved the study.

3 RESULTS

All 40 participants completed the study for 12

weeks. Analysis of baseline characteristics showed

no significant differences in selected cardio-

metabolic risk factors and fetuin-A (Table 1). After

12 weeks, both groups had reductions in weight,

BMI, WC, SBP, and DBP. Reduction in CRP was

also found in the placebo group; fetuin-A was

reduced in the metformin group. Compared to

placebo, weight, BMI, WC, FPG, 2h-PPG, HDL-C,

and TG had decreased significantly in the metformin

group (Table 2).

Table 1. Baseline Characteristic

Characteristicts Placebo group (n = 20)

Mean (SD)

Metformin group (n = 20)

Mean (SD)

Age, yr

40.1 (5.78) 42.7 (5.2)

0.149

Weight, kg

77.6 (11.0) 81.4 (14.6)

0.354

BMI, kg/m²

32.1 (4.1) 34.2 (5.6)

0.180

WC, cm

95.7 (7.3) 97.9 (11.5)

0.449

SBP, mmHg

123.5 (11.4) 127.0 (20.3)

0.989

DBP, mmHg

82.2 (10.5) 80.8 (11.0)

0.495

HDL-C, mg/dL

46.4 (8.5) 48.9 (16.4)

0.968

TG, mg/dL

147.5 (30.6) 152.3 (66.9)

0.799

FPG, mg/dL

83.4 (10.6) 84.9 (8.9)

0.341

2h-PPG, mg/dL

114.9 (35.4) 105.1 (22.4)

0.602

HOMA-IR

1.13 (0.94) 1.0 (0.6)

0.700

CRP, mg/dL

3.6 (2.5) 3.9 (2.4)

0.699

Fetuin-A, µg/mL

461.4 (74.6) 459.0 (62.8)

0.911

TGF-ß1, pg/mL

47479,34 (6942.01) 45272.06 (3711.22)

0.380

Effect of Lifestyle Modiﬁcation and Metformin on Fetuin-A and Transforming Growth Factor-ß (TGF- ß) in Metabolic Syndrome

467

Table 2. Change in selected cardio-metabolic risk factors from baseline and at 12 weeks, N= 40.

Parameter

Placebo group

(n=20)

Metformin group

(n=20)

Baseline

weeks

Difference P Baseline

weeks

Difference P

Weight (SD),

77.6

(11.0)

75.2

(10.8)

-2.3

0.00

1**

81.4

(14.6)

77.4

(14.5)

-3.9 0.001** 0.001**

BMI (SD),

kg/m²

32.1 (4.1)

30.9

(4.1)

-1.1

0.00

1**

342 (5.6)

32.4

(5.6)

-1.8 0.001** 0.002**

WC (SD), cm

95.7 (7.3)

89.9

(7.5)

-5.8

0.00

1**

97.9

(11.5)

91.8

(10.7)

-6.2 0.001** 0.047*

SBP (SD),

mmHg

123.5

(11.4)

114.0

(8.2)

-9.5

0.00

7**

127.0

(20.3)

112.8

(8.5)

-14.3 0.001** 0.160

DBP (SD),

mmHg

82.2

(10.5)

69.0

(5.5)

-31.8

0.00

1**

80.6

(11.0)

67.5

(7.2)

-13.3 0.001** 0.089

HDL-C (SD),

mg/dL

46.4 (8.5)

45.3

(10.0)

-1.1

0.62

489 (16.4)

45.5

(9.8)

-2.4 0.653 0.043*

TG (SD),

mg/dL

147.5

(50.5)

153.3

(67.9)

5.8

0.63

152.3

(66.9)

149.0

(102.4)

-3.3 0.147 0.045

FPG (SD),

mg/dL

83.4

(10.6)

91.7

(20.6)

8.3

0.00

1**

84.9 (8.9)

87.7

(10.7)

2.8 0.305 0.013*

2h-PPG

(SD), mg/dL

114.9

(35.4)

112.5

(37.7)

-2.5

0.71

105 (22.4)

102.3

(19.3)

-2.8 0.491 0.007**

HOMA-IR

(SD)

1.13

(0.94)

1.68

(0.25)

-0.5

0.61

1.03

(0.61)

1.03

(0.4)

0 0.956 1.000

CRP (SD),

mg/dL

3.6 (2.5)

3.0

(2.2)

-0.6

0.04

3.9 (2.4)

3.5

(1.9)

-0.6 0.327 0.133

Fetuin-A

(SD), µg/mL

461.4

(74.6)

42.6

(84.8)

-34.8

0.15

459.0

(62.8)

398.1(

101.4)

-610 0.005** 0.477

TGF-ß1

(SD), pg/mL

47479.34

(6942.01)

47346.

(6654.

11)

-132.65

1.00

45272.06

(3711.22)

4458.7

(8232.

-1013.35 0,661 0.353

4 DISCUSSION

Obesity is the most common risk factor for MetS

and NAFLD (Reinehet al., 2008). As suggested by

novel evidence, hepatocytes from fatty liver release

factors called hepatokines (e.g., fetuin-A, sex

hormone-binding globulin) into the circulation that

are directly involved in local pathogenesis, systemic

inflammation and hepatic insulin resistance (Reaven

et al., 1988). The fetuin-A levels of obese children

are apparently similar to those of adults (Ohkawaraet

al., 2007). A study by Mori and colleagues did not

find a significant association between fetuin-A and

insulin resistance in type 2 diabetic subjects (Mori et

al., 2006).In contrast, other studies demonstrated a

relationship between fetuin-A and insulin resistance

in adults without T2D (Stefan et al., 2006).Fetuin-A

concentrations decreased significantly in obese

children after substantial weight loss after 1 year but

were apparently unchanged in those who did not

lose weight (Ohkawaraet al., 2007). Our study found

that fetuin-A decreased significantly with LSM and

metformin treatment for 12 weeks, possibly

associated with weight reduction.

ICTROMI 2019 - The 2nd International Conference on Tropical Medicine and Infectious Disease

468

A recent systematic review showed a dose-response

effect of aerobic exercise on visceral adiposity, but

the ability of exercise to reduce visceral adipose

tissue was less robust in those with metabolic

disorders (Wing et al., 2001). It remains unclear if

the same dose-response effect on central adiposity

will also be seen in those with MetS. Nevertheless,

during weight maintenance, regular exercise still has

an important role in abdominal fat loss and may help

prevent weight regain in those who have

successfully lost weight (Ross et al., 2004).

However, even in the absence of weight loss,

exercise has been shown to reduce visceral adipose

tissue (Stone et al., 2005). Our study demonstrated

that weight, BMI and WC decreased significantly in

the course of 12 weeks of LSM in both groups.

The National Cholesterol Education Program

Adult Treatment Panel III (NCEP: ATP-III)

recommends LDL-C reduction as the primary

treatment goal for CVD risk reduction. Therapeutic

lifestyle changes, particularly improvement in

physical activity and weight management, need to be

instituted in those individuals with the Mets to

address elevated TG and low HDL-C (Kelley, 2007).

Although aerobic exercise training has generally

been shown to increase HDL-C and decrease TG, its

effects on LDL-C has been mixed (Kodama et al.,

2007, Stefanick et al., 1998). Beneficial effects of

exercise training on lipids and lipoproteins may have

an additional impact when combined with dietary

modification and weight loss (Whelton et al., 2002).

Our study demonstrated HDL-C and TG did not

decrease significantly in the course of 12 weeks of

LSM on both groups.

A recent meta-analysis of randomized controlled

trials studying the effect of aerobic exercise on BP

showed a reduction in systolic and diastolic BP by

approximately 3.8 and 2.6 mmHg, respectively

(Bacon et al., 2004). Although the effect of aerobic

exercise on blood pressure is small and not

consistently observed in all studies, there may be

additional benefit when combined with dietary

modification and/or weight loss (Cornier et al.,

2008). Our study demonstrated significant

reductions in systolic and diastolic BP in both

groups in the course of 12 weeks of LSM.

Insulin resistance is another core component of

the Mets that requires careful attention. Weight loss

and LSM can lead to clinically meaningful

improvements in insulin sensitivity and should be

considered the primary therapeutic options for

treating insulin resistance. The difficulties and

frustrations associated with weight loss efforts and

LSM have driven the demand for using

pharmaceutical agents that target insulin resistance

in a more direct fashion. The exact role for these

agents is less clear. Several randomized controlled

trials have shown that agents targeting insulin

resistance can help prevent the progression to T2D

in individuals with impaired glucose tolerance

(IGT). These studies did not directly target

individuals with the Mets. It is unclear whether these

agents truly prevent progression to T2D or simply

treat glucose intolerance or mild hyperglycemia. In

addition, studies have not clearly shown whether

these agents improve cardiovascular outcomes. As

with weight loss medications, the goals for the use

of agents targeting insulin resistance must be clear

(Henniger al., 2008). Our study demonstrated

HOMA-IR did not decrease significantly in both

groups.

Fetuin-A induces low-grade inflammation, which

is also associated with MetS and an atherogenic lipid

profile (Reiner et al., 2008, Ridker, 2001).

Inflammation assessed by elevated CRP

measurements has been linked to excess

cardiovascular risk and Mets (Ridker et al., 2003,

Gonzálezet al

., 2006). CRP is a general marker of

inflammation, making it suitable to assess in

individuals with metabolic syndrome. Elevated

levels of CRP are associated with increased WC,

insulin resistance, BMI and hyperglycemia; and in

the presence of more components of the Mets

(Deepa et al., 2006, Guldikenet al., 2007, Bahia et

al., 2006, Gonzálezet al., 2006, Clearfield, 2005).

Because Mets have been linked with a greater

chance of future cardiovascular events, CRP levels

may be an important independent predictor of

unfavorable outcomes in those already with Mets

(Van Dillen et al., 2004). There are, however, no

currently recommended direct therapies targeting

inflammation. LSM and weight loss result in

decreased CRP concentrations, as does the treatment

of the other associated comorbidities such as

dyslipidemia, elevated blood pressure, insulin

resistance and hyperglycemia (Devaraj, 2007,

Knowles et al., 2002). Our study observed CRP

decreased significantly only in the placebo group.

It has not been determined how the Pro 10

variant form of the TGF-β1 protein is linked to

visceral adiposity and elevated levels of circulating

insulin, there is a possibility that TGF-β1 is involved

in the insulin resistance with obesity. Since

macrophage infiltration into adipose tissue causes

insulin resistance and since coculture experiments

with human adipocytes and macrophages have

shown that downstream effectors of TGF-β such as

PAI-1, collagen VI, and phosphorylated Smad were

Effect of Lifestyle Modiﬁcation and Metformin on Fetuin-A and Transforming Growth Factor-ß (TGF- ß) in Metabolic Syndrome

469

increased in both macrophages and adipocytes,

TGF-β has the potential for increasing insulin

resistance (Ken-ichi, 2011).

In experimental animal studies, Samad et al.

reported enhancement of gene and protein

expression of TGF-β1 in two strains of genetically

obese mice (ob/ob and DB/DB) compared with that

in lean mice(Samad, 1997) and Raju et al. showed

that an obese state increases levels of TGF-β1 but

not TGF-β2 in platelets of Zucker rats, recognized as

an experimental model of Mets (Raju, 2006).

Moreover, Sciarretta et al. showed that serum levels

of inflammatory markers, including C-reactive

protein, tumor necrosis factor-alpha, and TGF-β, in

hypertensive patients with MetS were significantly

higher than those in patients without MetS (Ken-

ichi, 2011).

5 CONCLUSION

LSM decreased CRP, human fetuin-A

concentrations, TGF-ß and selected cardio-metabolic

risk factors in this 12-week study. These findings

raise the possibility that fetuin-A may directly

promote the Mets phenotype in humans and there is

a possibility that TGF-ß is involved in the insulin

resistance with obesity. The selected cardio-

metabolic factors significantly improved with

metformin to the same degree as with the LSM.

Longitudinal and larger scale studies are needed to

evaluate the direction of the observed associations,

the regulatory factors that alter serum fetuin-A

concentrations, its effects on cardiovascular events,

and the long-term effects of metformin on selected

cardio-metabolic risk factors.

CONFLICT OF INTERESTS

The authors declare that there is no conflict of

interests regarding the publication of this paper.

REFERENCES

Bacon SL, Sherwood A, Hinderliter A, Blumenthal J.

2004. Effects of exercise, diet and weight loss on high

blood pressure. Sports Med. 34(5):307-16.

Bahia L, Aguiar LG, Villela N, Bottino D, Godoy-Matos

AF, Geloneze B, et al. 2006. Relationship between

adipokines, inflammation, and vascular reactivity in

lean controls and obese subjects with metabolic

syndrome. Clinics (Sao Paulo). 61(5):433-40.

Bruce KD, Byrne CD. 2009. The metabolic syndrome:

Common origins of a multifactorial disorder. Postgrad

Med J. 85(1009):614-21.

Clearfield MB.2005. C-reactive protein: A new risk

assessment tool for cardiovascular disease. J Am

Osteopath Assoc. 105(9):409-16.

Cornier MA, Dabelea D, Hernandez TL. 2008. The

metabolic syndrome. Endocrine Rev. 29(7):777-822.

Deepa R, Velmurugan K, ArvindKet, Sivaram P, Sientay

C, Uday S, et al. 2006. Serum levels of interleukin 6,

C-reactive protein, vascular cell adhesion molecule 1,

and monocyte chemotactic protein 1 in relation to

insulin resistance and glucose intolerance—The

Chennai Urban Rural Epidemiology Study (CURES).

Metabolism. 55(9):1232-8.

Devaraj S, Rogers J, Jialal I. 2007. Statins and biomarkers

of inflammation. CurrAtheroscler Rep. 9(1):33-41.

Eckel RH, Grundy SM, Zimmet PZ. 2005. The metabolic

syndrome.Lancet. 365(9468):1415-28.

Glueck CJ, Fontaine RN, Wang P, Subbiah MT, Weber K,

Illig E, et al. 2001. Metformin reduces weight,

centripetal obesity, insulin, leptin, and low-density

lipoprotein cholesterol in nondiabetic, morbidly obese

subjects with body mass index greater than 30.

Metabolism. 50(7):856-61.

González AS, Guerrero DB, Soto MB, et al. 2006.

Metabolic syndrome, insulin resistance and the

inflammation markers C-reactive protein and ferritin.

Eur J Clin Nutr. 60(6):802-9.

González AS, Guerrero DB, Soto MB, et al. 2006.

Metabolic syndrome, insulin resistance and the

inflammation markers C-reactive protein and ferritin.

Eur J Clin Nutr. 60(6):802-9.

Grundy SM. 2004. Obesity, metabolic syndrome, and

cardiovascular disease. J ClinEndocrinolMetab.

89(6):2595-600.

Guldiken S, Demir M, Arikan E, Turgut B, Azcan S,

Gerenli M, et al. 2007. The levels of circulating

markers of atherosclerosis and inflammation in

subjects with different degrees of body mass index:

Soluble CD40 ligand and high-sensitivity C-reactive

protein. Thromb Res. 119(1):79-84.

Hennige AM, Staiger H, Wicke C, Machiaco F, Fritsche

A, Haring HU, et al. 2008. Fetuin-A induces cytokine

expression and suppresses adiponectin production.

PLoS One. 3(3):e1765.

International Diabetes Federation. 2006. The IDF

consensus worldwide definition of the metabolic

syndrome. Brussels: International Diabetes Federation.

http://www.idf.org/webdata/docs/

IDF_Meta_def_final.pdf.

Ix JH, Wassel CL, Chertow GM, Koster A, Johnson KC,

Tylavsky FA, et al. 2009. Fetuin-A and change in

body composition in older persons. J

ClinEndocrinolMetab. 94(11):4492-8.

Kelley GA, Kelley KS. 2007. Effects of aerobic exercise

on lipids and lipoproteins in adults with type 2

diabetes: A meta-analysis of randomized controlled

trials. Public Health. 121(9):643-55.

ICTROMI 2019 - The 2nd International Conference on Tropical Medicine and Infectious Disease

470

Ken-ichi A, Yasumasa I, Shusuke Y, Masashi A, and

Toshio M. 2011. Transforming growth factor-ß1 as a

common target molecule for the development of

cardiovascular diseases, renal insufficiency, and

metabolic syndrome. Cardiology research and

practice.

Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF,

Lachin JW, Walker EA. et al. 2002. Reduction in the

incidence of type 2 diabetes with lifestyle intervention

or metformin. N Engl J Med. 346(6):393-403.

Kodama S, Tanaka S, Saito K, Shu M, Sone Y, Onitake F,

et al. 2007. Effect of aerobic exercise training on

serum levels of high-density lipoprotein cholesterol: A

meta-analysis. Arch Intern Med. 167(10): 999-1008.

Lin HZ, Yang SQ, Chuckaree C, Kuhadja F, Ronnet G,

Diehl AM, et al. 2000. Metformin reverses fatty liver

disease in obese, leptin-deficient mice. Nat Med.

6(9):998-1003.

Mazza A, Fruci B, Garinis GA, Giuliano S, Malaguarnera

R, Belfiore A, et al. 2012. The role of metformin in the

management of NAFLD.Exp Diabetes Res.

2012:716404.

Miller WC, Koceja DM, Hamilton EJ.1997. A meta-

analysis of the past 25 years of weight loss research

using diet, exercise or diet plus exercise intervention.

Int J Obes Relat Metab Disord. 21(10):941-7.

Misra A, Misra R, Wijesuriya M. 2007. The metabolic

syndrome in South Asians. In: Mohan V, RaoGundu

HR, eds. Type 2 diabetes in South Asians.

Epidemiology, risk factors, and prevention. New

Delhi: Jaypee Bros., 76-96.

Mori K, Emoto M, Yokoyama H, Araki T, Teramura M,

Koyama H, et al. 2006. Association of serum fetuin-A

with insulin resistance in type 2 diabetic and

nondiabetic subjects. Diabetes Care. 29(2):468.

Ohkawara K, Tanaka S, Miyachi M, Ishikawa-Takata K,

Tabata I. 2007. A dose-response relation between

aerobic exercise and visceral fat reduction: Systematic

review of clinical trials. Int J Obes. 31(12):1786-97.

Orchard TJ, Temprosa M, Goldberg R, Haffner S, Rather

R, Marcovina S, et al. 2005. The effect of metformin

and intensive lifestyle intervention on the metabolic

syndrome: The Diabetes Prevention Program

randomized trial. Ann Intern Med. 142(8):611-9.

Pasquali R, Gambineri A, Biscotti D, Viccenati V,

Gagliardi L, Colitta D, et al. 2000. Effect of long-term

treatment with metformin added to hypocaloric diet on

body composition, fat distribution, and androgen and

insulin levels in abdominally obese women with and

without the polycystic ovary syndrome. J

ClinEndocrinolMetab. 85(8):2767-74

Perkeni. 2011. KonsensusPengelolaandanPencegahan

Diabetes Mellitus Type 2 Di Indonesia.

PerkumpulanEndokrinologi Indonesia.

Raju J, Bajaj G, Chrusch J, and Bird RP. 2006. Obese state

leads to elevated levels of TGF-β and COX isoforms

in platelets of Zucker rats,"Molecular and Cellular

Biochemistry. 284(1) 19–24.

Ratner R, Goldberg R, Haffner S, Marcovina S, Orchard

T, Fowler S, et al. 2005. Impact of intensive lifestyle

and metformin therapy on cardiovascular disease risk

factors in the diabetes prevention program. Diabetes

Care. 28(4):888-94.

Reaven GM. 1988. Banting lecture 1988. Role of insulin

resistance in human disease.Diabetes. 37(12):1595-

607.

Reinehr T, Roth CL. 2008. Fetuin-A and its relation to

metabolic syndrome and fatty liver disease in obese

children before and after weight loss. J

ClinEndocrinolMetab. 93(11):4479-85.

Ridker PM. 2001. High-sensitivity C-reactive protein:

Potential adjunct for global risk assessment in the

primary prevention of cardiovascular disease.

Circulation. 103(13):1813-8.

Ridker PM, Buring JE, Cook NR, et al. 2003. C-reactive

protein, the metabolic syndrome, and risk of incident

cardiovascular events: an 8-year follow-up of 14719

initially healthy American women. Circulation.

107(3):391-7.

Ross R, Janssen I, Dawson J, et al. 2004. Exercise-induced

reduction in obesity and insulin resistance in women: a

randomized controlled trial. Obes Res. 12(5):789-98.

Samad F, Yamamoto K, Pandey M, and Loskutoff DJ.

1997. Elevated expression of transforming growth

factor-β in adipose tissue from obese mice, Molecular

Medicine, 3(1)37–48

Sharoff CG, Hagobian TA, Malin SK, et al. 2010.

Combining short-term metformin treatment and one

bout of exercise does not increase insulin action in

insulin-resistant individuals. Am J Physiol Endocrinol

Metab. 298(4): E815-23.

Srinivas PR, Wagner AS, Reddy LV, et al. 1993. Serum

alpha 2-HS-glycoprotein is an inhibitor of the human

insulin receptor at the tyrosine kinase level.

MolEndocrinol. 7(11):1445-55.

Stefan N, Hennige AM, Staiger H, et al. 2006. Alpha 2-

Heremans-Schmid glycoprotein/fetuin-A is associated

with insulin resistance and fat accumulation in the

liver in humans. Diabetes Care. 29(4):853-7.

Stefanick ML, Mackey S, Sheehan M, et al. 1998. Effects

of diet and exercise in men and postmenopausal

women with low levels of HDL- cholesterol and high

levels of LDL-C cholesterol. N Engl J Med.

339(1):12-20.

Stone NJ, Bilek S, Rosenbaum S. 2005. Recent National

Cholesterol Education Program Adult Treatment Panel

III update: adjustments and options. Am J Cardiol.

96(4A):53E-9E.

UK Prospective Diabetes Study (UKPDS) Group. 1998.

Effect of intensive blood-glucose control with

metformin on complications in overweight patients

with type 2 diabetes (UKPDS 34).UK Prospective

Diabetes Study (UKPDS) Group.Lancet.

352(9131):854-65.

Van Dielen FM, Buurman WA, Hadfoune M, Nijhuis J,

Greve JW. 2004. Macrophage inhibitory factor,

plasminogen activator inhibitor-1, other acute phase

proteins, and inflammatory mediators normalize as a

result of weight loss in morbidly obese subjects treated

Effect of Lifestyle Modiﬁcation and Metformin on Fetuin-A and Transforming Growth Factor-ß (TGF- ß) in Metabolic Syndrome

471

with gastric restrictive surgery. J

ClinEndocrinolMetab. 89:4062-8.

Whelton SP, Chin A, Xin X, He J. 2002. Effect of aerobic

exercise on blood pressure: A meta-analysis of

randomized, controlled trials. Ann Intern Med.

136(7):493-503.

WHO Expert Consultation. 2004. Appropriate body-mass

index for Asian populations and its implications for

policy and intervention strategies.Lancet.

363(9403):157-63.

Wing RR, Hill JO. 2001. Successful weight loss

maintenance. Ann Rev Nutr 21:323-41.

Wulffelé MG, Kooy A, de Zeeuw D, Stehouwer CD,

Gansevoort RT. 2004. The effect of metformin on

blood pressure, plasma cholesterol, and triglycerides in

type 2 diabetes mellitus: A systematic review. J Intern

Med. 256(1):1-14.

ICTROMI 2019 - The 2nd International Conference on Tropical Medicine and Infectious Disease

472