Georgios Valsamakis

Association of simple anthropometric measures of obesity with visceral fat and the metabolic syndrome in male Caucasian and Indo-Asian subjects

Aims  The aims of this study were first, to investigate the relationship between simple anthropometric measures of obesity with visceral fat as assessed by a single slice magnetic resonance imaging (MRI)‐scan in patients attending a hospital clinic. Second, to determine which anthropometric measure best relates to the adverse metabolic profile of the metabolic syndrome.

Fasting serum adiponectin concentration is reduced in Indo-Asian subjects and is related to HDL cholesterol

Aims: Adiponectin is a 30‐kDa protein secreted by adipose tissue. The aim of the present study was to compare serum adiponectin in male Indo‐Asian and Caucasian subjects and examine its association with fat topography and metabolic parameters.

The effects of adipose tissue and adipocytokines in human pregnancy

During pregnancy, important changes take place in maternal metabolism because of the growing fetus and placental formation. The increase in insulin resistance during pregnancy is paralleled by the progressive increase of maternal adipose tissue deposition. This review examines the topography of fat mass deposition during pregnancy in relation to factors such as parity and maternal age that might affect this deposition. We also examine adipose tissue markers, such as pregravid weight and weight gain during pregnancy, and their effect on fetal growth and pregnancy outcomes. In addition, this review studies the possible effects of cytokines that are produced by adipose tissue and the placenta on maternal metabolism and its complications. Finally, we also consider the possible role of maternal adipocytokines and fetal adipocytokines on fetal growth.

Effect of the orlistat on serum endotoxin lipopolysaccharide and adipocytokines in South Asian individuals with impaired glucose tolerance

Background:  Orlistat has been shown to increase adiponectin and reduce progression to type 2 diabetes in obese Caucasians. Some effects of orlistat are thought to be independent of weight loss by altering gut flora and the production of endotoxin lipopolysaccharide (LPS). We studied the effect of dietary treatment with and without orlistat in South Asian individuals with impaired glucose tolerance (IGT) on adiponectin and inflammatory markers including LPS.

Detection of impaired glucose tolerance and undiagnosed type 2 diabetes in UK South Asians : an effective screening strategy

Aim:  We tested a stepwise, community‐based screening strategy for glucose intolerance in South Asians using a health questionnaire in conjunction with body mass index (BMI). Anthropometric measurements (waist and hip circumference, sagittal diameter and percentage body fat) were then conducted in a hospital setting followed by an oral glucose tolerance test (OGTT) to identify subjects at the highest risk and analyse the factors predicting that risk.

Probing the impact of sex steroids and menopause-related sex steroid deprivation on modulation of immune senescence.

Immune senescence denotes the general decline in immune system function, characterized by a reduced immune response and an increased inflammatory state. Menopause is a natural change in a womens life, the menopause-related low estrogen levels affecting many body functions, among them the immune system. Numerous human studies with menopausal women and animal models with surgically induced menopause show a clear impact of sex steroids in immune responses. Female superiority in vaccination response and predisposition to infections are eliminated after menopause, while during menopause inflammatory cytokines such as Tumor Necrosis Factor-α (TNF-α), Interleukins-1β, 6, 8 and 13 (IL-1β, IL-6, IL-8, IL-13) and Monocyte Chemoattractant Protein-1 (MCP-1) are increased, implying a molecular connection of sex steroid loss with immune senescence. Moreover, immune cells modify their number and function after the menopausal transition, this offering another explanation for immune senescence. Until now most of the existing studies have concluded that menopause plays an additional role to aging in immune senescence. While it is clear that we are as yet far from thoroughly understanding the molecular pathways connecting sex steroids and menopause with immune senescence, such knowledge is highly likely to enable future targeted interventions in treatment and prevention of age-related diseases in women.

The role of maternal gut hormones in normal pregnancy: fasting plasma active glucagon-like peptide 1 level is a negative predictor of fetal abdomen circumference and maternal weight change.

OBJECTIVE Maternal weight in pregnancy contributes to a glycemic environment that affects fetal growth. Gut peptides (glucagon-like peptide 1 (GLP1), glucose-dependent insulinotropic peptide (GIP), ghrelin, and peptide YY (PYY)) have been related to insulin sensitivity and secretion, weight control, and adipose tissue metabolism. This study aimed at examining the associations of gut hormones during pregnancy with maternal glucose homeostasis, maternal weight, and fetal growth. METHODS A total of 55 pregnant nonobese, nondiabetic Caucasian women were examined during the three trimesters of pregnancy, and anthropometric measurements, evaluation of fasting maternal plasma GLP1 (active), ghrelin (active), total PYY, total GIP, and a 75-g oral glucose tolerance test were done in them. Homeostasis model assessment (HOMA-R), insulin sensitivity index (ISI), and indices of insulin secretion were calculated. Fetal growth was estimated by ultrasound. RESULTS Fasting GLP1 increased significantly from the second to the third trimester (P<0.05). Fasting GLP1 correlated positively with high-density lipoprotein cholesterol (r=0.52, P=0.04). At the second trimester, fasting GLP1 levels correlated negatively with fetal abdomen circumference (r=-0.55, P=0.034), birth weight (r=-0.50, P=0.040), HOMA-R (r=-0.65, P=0.001), insulin secretion, and triglycerides. At the first trimester, fasting ghrelin levels correlated negatively with HOMA-R and insulin secretion, and positively with ISI. In backward multiple regression analysis, the first trimester GLP1 levels were the best negative predictors of the second trimester fetal abdomen circumference (beta=-0.96, P=0.009). In longitudinal regression model, maternal fat and HOMA-R were the positive predictors of maternal weight change during pregnancy, and fasting GLP1 levels were the negative predictors of maternal weight change during pregnancy. CONCLUSIONS During pregnancy, maternal GLP1 might be involved in mechanisms that compensate for the pregnancy-related increase in glycemia and insulin resistance, suggesting a role of this peptide in maternal metabolism and weight and fetal growth.

Study of carbohydrate metabolism indices and adipocytokine profile and their relationship with androgens in polycystic ovary syndrome after menopause

OBJECTIVE Hyperandrogenism, insulin resistance, and altered adipocytokine levels characterize polycystic ovary syndrome (PCOS) women of reproductive age. Hyperandrogenism persists in postmenopausal PCOS women. In the latter, this study aimed at investigating carbohydrate metabolism, adipocytokines, androgens, and their relationships. SUBJECTS AND METHODS Blood sampling from overweight postmenopausal women (25 PCOS and 24 age- and BMI-matched controls) at baseline and during oral glucose tolerance test for measurement of insulin and glucose levels, baseline leptin, adiponectin, visfatin, retinol-binding protein 4, lipocalin-2, androgen, and high-sensitivity C-reactive protein (hs-CRP) levels and for calculation of insulin sensitivity (glucose-to-insulin ratio (G/I), quantitative insulin sensitivity check index, and insulin sensitivity index (ISI)), resistance (homeostasis mathematical model assessment-insulin resistance (HOMA-IR)), secretion (Δ of the area under the curve of insulin (ΔAUCI), first-phase insulin secretion (1st PHIS), and second-phase insulin secretion (2nd PHIS)), and free androgen indices (FAI). RESULTS PCOS women had higher insulin secretion indices, hs-CRP, androgen, and FAI levels than controls without differing in baseline glucose, insulin and adipocytokines levels, insulin sensitivity, and resistance indices. In PCOS women, FAI levels correlated positively with baseline insulin, ΔAUCI, HOMA-IR, and ΔAUCG and negatively with G/I; hs-CRP levels correlated positively with ΔAUCI and negatively with ISI. PCOS status, waist circumference, and 17-hydroxyprogesterone (17-OHP) levels were positive predictors for ΔAUCI. In all women, waist circumference was a negative predictor for ISI; 17-OHP and FAI levels were positive predictors respectively for baseline insulin levels and for 1st PHIS and 2nd PHIS. CONCLUSIONS Early postmenopausal PCOS women are characterized by hyperinsulinemia but attenuated insulin resistance. PCOS status and waist circumference are predictors of hyperinsulinemia while insulin sensitivity correlates negatively with FAI. The differences reported in adipocytokine levels between PCOS and non-PCOS women in reproductive years seem to disappear after menopause.

MRI total sagittal abdominal diameter as a predictor of metabolic syndrome compared to visceral fat at L4–L5 level

ABSTRACT Objective: To compare associations between antero-posterior (AP) diameter or sagittal abdominal diameter – a measure of total central fat, and visceral fat alone with the metabolic syndrome as defined by ATPIII criteria. Research design and methods: Twenty-four Caucasian male with type 2 diabetes and 24 non-diabetic Caucasian male subjects [body mass index (BMI) (±SD): 32.23 ± 7.52 kg/m2, age (±SD): 51.35 ± 13.80 years] were studied by magnetic resonance imaging (MRI) scan to measure central fat at L4–L5 level. The visceral and total central adipose tissue was calculated in cm2 and total sagittal MRI diameter and visceral sagittal MRI diameters in cm. Components of the ATPIII definition of the metabolic syndrome and circulating adipocytokine concentrations were also measured. Results: MRI total sagittal abdominal diameter was positively associated with waist circumference in controls (r = 0.62, p = 0.007) and in diabetic subjects (r = 0.81, p < 0.001). Binary logistic regression analysis showed that MRI-calculated total sagittal diameter (r = 0.61, p = 0.002) was a more significant predictor of the adverse metabolic profile of the metabolic syndrome than MRI-assessed visceral fat. Receiver operating characteristic curves revealed that MRI-calculated total sagittal diameter most effectively identified subjects with the metabolic syndrome. Conclusions: MRI-calculated total sagittal abdominal diameter is a non-validated MRI method that predicts the adverse metabolic profile of the ATPIII definition of the metabolic syndrome. Antero-posterior fat is a dimension of central fat that seems to be more closely associated with cardiovascular risk compared to visceral fat.

The Management of Obesity in Type 2 Diabetes Mellitus

SUMMARY Prevalence of obesity in the United Kingdom has tripled in the last 20 years and this is driving an epidemic of type 2 diabetes. Indeed, today the vast majority of patients with type 2 diabetes are overweight or obese. Effective weight management leading to modest weight loss to the order of 5-10% of body weight can lead to significant clinically meaningful benefits provided it can be maintained. Thus weight management can lead to improved glycaemic control, better blood pressure control and lipid control in addition to other benefits. Management of diabetic patients who are obese requires management also of other associated co-morbid conditions and it is important to ensure that glycaemic control does not deteriorate during weight management. An integrated approach to weight management in the diabetic patient is recommended which helps to promote lifestyle modification for all patients. Drug therapy may be appropriate for many obese patients who do not reach target weight loss with lifestyle modification alone. Surgery should be reserved for those with BMI >40 only after failed medical therapy.