Association of Elevated Serum Uric Acid with the Components of Metabolic Syndrome and Oxidative Stress in Abdominal Obesity Subjects

Abdominal obesity (AO) and metabolic syndrome (MetS) are associated with the cardiovascular disease and type 2 diabetes. Serum uric acid (SUA) is often elevated in subjects with the AO. We aimed to investigate the association of elevated SUA with the components of MetS, oxidative stress and TG/HDL-C ratio in AO subjects. This cross-sectional study used data from a Health Survey for Prevention of Hypertension and Type 2 Diabetes Mellitus in residents of two districts in Phitsanulok province, including 443 subjects. Anthropometric, blood pressure (BP) and biochemical variables were measured. We categorized the participants to two-group as 248 AO subjects (median age = 58, interquartile range 50.0–65.0 years) and 195 non-AO subjects (median age = 53, interquartile range 47.0–62.0 years). Waist circumference was significantly correlated with SystBP, DiastBP, Glu and SUA (P < 0.05) and SUA was significantly correlated with Glu, TG, HDL-C and TG/HDL-C ratio (P < 0.05). By using multiple logistic regression, we found the association of elevated SUA with abdominal obesity, hyperglycemia, hypertriglyceridemia, reduced HDL-C, elevated TG/HDL-C ratio, MetS and increased oxidative stress after adjusting for their covariates. Our study demonstrated that circulating UA is a major antioxidant and might help protect against free-radical oxidative damage. However, elevated SUA concentrations associated with oxidative stress, MetS, insulin resistance, and components of MetS. Then, SUA may be a marker of increased oxidative stress, insulin resistance and MetS, implying an increased risk of vascular disease and T2DM.     

Hypoadiponectinemia in Obesity: Association with Insulin Resistance

Obesity is risk factor for insulin resistance, diabetes, and other chronic diseases. Adiponectin, an adipose-specific protein with antiatherogenic and antiinflammatory effects, were found to be associated with obesity, type 2 diabetes, and insulin resistance. Our aim to identify possible relationships between circulating adiponectin and obesity as well as obesity related phenotypes. A total of 642, obese and non-obese individuals were included in this cross-sectional study. Hormone and glucose levels were estimated using standard protocols. The adiponectin levels showed a significant decrease with increasing quartiles of insulin resistance index. Subjects in lowest quartile of adiponectin level had a significantly higher risk than those in the highest quartile, with higher body mass index, waist circumference, blood pressure, percentage body fat, fat mass, fasting insulin, insulin resistance index, total cholesterol (p < 0.001), low density lipoprotein–cholesterol (p = 0.001), very low density lipoprotein–cholesterol (p = 0.002), and Triglyceride (p = 0.002). The present study indicates that adiponectin is significantly associated with obesity, insulin resistance and other obesity related phenotypes.     

Angiogenic Potential,Circulating Angiogenic Factors and Insulin Resistance in Subjects with Obesity

Altered vascular function and pathological angiogenesis are important factors common to the development of obesity and obesity-associated diseases. Most human studies relating obesity and angiogenesis have compared levels of angiogenic factors in obesity without looking at the serum angiogenic capacity which reflects the balance between the effects of angiogenic and angiostatic factors. Therefore, in this cross-sectional study, the serum angiogenic potential and levels of angiogenic factors in serum of obese (BMI > 25 kg/m²) and lean subjects (BMI < 23 kg/m²), with no history of obesity associated co-morbidities, were assessed. Serum angiogenic potential was significantly higher (p < 0.0001) in both male (n = 67) and female (n = 35) obese subjects and showed a positive correlation (r = 0.4, p < 0.0001) with BMI. Serum levels of the angiogenic factors, vascular endothelial growth factor (VEGF) and angiopoietin were significantly higher in obese subjects. Levels of angiostatic factors such as angiostatin, endostatin were not altered in obese male subjects but were elevated in female obese subjects. Angiogenic potential and levels of VEGF did not vary in obese subjects with high HOMA-IR compared to obese subjects with low HOMA-IR. These results suggest that the angiogenic potential of serum was elevated in obesity and that insulin resistance may not contribute to the increased angiogenic potential in obesity.     

Comparison Between Serum Insulin Levels and Its Resistance With Biochemical,Clinical and Anthropometric Parameters in South Indian Children and Adolescents

There is a rising trend in the prevalence of insulin resistance among obese, overweight children and adolescents. The serum insulin and its correlation with biochemical, clinical and anthropometric parameters were evaluated in 185 children and adolescents (59 control, 52 obese, 49 overweight, 25 congenital heart disease) of age group 10–17 years. The levels of serum insulin were measured by ELISA. Serum insulin levels were found to be significantly increased in children who were obese, overweight and had congenital heart disease, than controls. Serum insulin levels positively correlated with BMI, WHR, and serum C-peptide, serum leptin, total cholesterol, triglycerides, LDL-cholesterol, systolic and diastolic blood pressure. Fasting glucose levels were found to be negatively correlated with serum insulin levels. HDL-cholesterol levels were non-significant among the study groups. We identified nine obese children (five girls and four boys) with the features of metabolic syndrome and 69% of obese and overweight children were identified with insulin resistance. Insulin resistance was strongly associated with metabolic syndrome and its components, especially with central obesity and hypertriglyceridemia.     

Association of Insulin Resistance with Adipocytokine Levels in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) results from the derangement of adipocyte physiology and carbohydrate metabolism. Obesity and insulin resistance (IR) are integral features of MetS. The adipokine alterations in MetS often correlate with IR and body fat content. High adipose tissue content is associated with a decreased production of adiponectin and excessive production of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), all of which induce IR. The present study evaluated the adipokine alterations in MetS and their association with IR. The findings of the current study indicate that MetS is associated with significant decrease in adiponectin and increase in TNF-α and IL-6. The present study also found that the adipocyte derived inflammatory adipokines, TNF-α and IL-6 correlate with IR while the anti-inflammatory adipokines, adiponectin does not correlate with the degree and severity of IR.     

Correlations of Insulin Resistance and Serum Testosterone Levels with LH:FSH Ratio and Oxidative Stress in Women with Functional Ovarian Hyperandrogenism

Functional ovarian hyperandrogenism (FOH) is a form of polycystic ovary syndrome (PCOS) characterized by elevated circulating levels of androgens derived from the ovary. Insulin resistance (IR) is the most common etiological factor in women with FOH. IR causes the generation of increased oxidative stress (OS) and diminished antioxidant status. OS is directly correlated with both IR and testosterone levels, which consequently contribute to endocrine and biochemical alterations in FOH women. In the current study, elevations in total testosterone, free testosterone and luteinizing hormone (LH) levels accompanied by a decrease in follicle stimulating hormone (FSH) level leading to higher LH:FSH ratio were the prominent endocrine changes observed in women with FOH. A significant increase in fasting blood levels of glucose and insulin, as well as an elevated IR were also seen in FOH women, as compared to their age matched controls. Women with FOH have higher pro-oxidant and lower anti-oxidant levels in blood than their age matched controls. In FOH women, elevations in LH:FSH ratio and OS are correlated more with hyperandrogenemia than with IR. Of the androgens, free rather than total testosterone has better positive correlations with elevated LH:FSH ratio and OS, and hence, the former is a better predictive marker for the development of biochemical PCOS in women with FOH.     

Association of Resistin with Insulin Resistance and Factors of Metabolic Syndrome in North Indians

Metabolic syndrome (MetS) is a cluster of interrelated common clinical disorders. The role of resistin in insulin sensitivity and MetS is controversial till date. So, the aim of the present study was to investigate the relationship of plasma resistin levels with markers of the MetS in Indian subjects. In a case control study, total 528 subjects were selected for the study. 265 (194 male and 71 female) were cases (with MetS) and 263 (164 male and 99 female) were controls (without MetS). Required anthropometric measurements and calculations were carried out accordingly. All the Biochemical estimations were carried out according to standard protocol. Resistin level was measured by the standard protocol (By ELISA i.e. enzyme linked immunosorbent assay) as illustrated in the kit. Insulin level was also measured by the standard protocol as illustrated in the kit and insulin resistance was calculated by the standard procedures. Plasma resistin levels were significantly higher in cases compared with controls (male = 13.05 ± 4.31 vs. 7.04 ± 2.09 ng/ml; p ≤ 0.001 and female = 13.53 ± 4.14 vs. 7.42 ± 2.30 ng/ml; p ≤ 0.001). Plasma resistin levels were well correlated with waist circumference, glucose, triglycerides, waist/hip ratio, systolic and diastolic blood pressure, high density lipoprotein, total cholesterol, serum low density lipoprotein, serum very low density lipoprotein, insulin and insulin resistance. Plasma resistin levels were elevated in presence of the MetS and were associated with increased metabolic risk factors.     

Correlation of Adiponectin and Leptin with Insulin Resistance: A Pilot Study in Healthy North Indian Population

The increasing incidence of obesity, leading to metabolic complications is now recognized as a major public-health problem. Insulin resistance is a central abnormality of the metabolic syndrome, or syndrome X, originally hypothesized by Reaven Insulin resistance is more strongly linked to intra abdominal fat than to fat in other depots. Adipose tissue secretes numerous factors (adipokines) known to markedly influence lipid and glucose/insulin metabolism, oxidative stress, and cardiovascular integrity. Some of these adipokines have been shown to directly or indirectly affect insulin sensitivity through modulation of insulin signaling and the molecules involved in glucose and lipid metabolism. A pilot study was conducted with 80 healthy subjects who were non diabetic, non hypertensive and having no family history of hypertension, the aim was to evaluate the correlation of adiponectin and leptin levels with obesity and insulin resistance markers in healthy north Indian adult population. Serum leptin, adiponectin and insulin was estimated by sandwich ELISA method. In our study, Leptin correlated significantly with BMI (P value of 0.0000), WC (P value = 0.007), and HC (P value = 0.000). leptin showed significant positive correlation with fasting insulin (P value 0.002), post prandial insulin (P value = 0.000) and HOMA-IR (P value = 0.002). Adiponectin showed significant positive correlation with triglycerides (P value = 0.038), strong negative correlation with HDL-cholesterol (P value = 0.017). Serum concentrations of leptin are associated with central body fat distribution. Insulin resistance and adiponectin is associated with dyslipidemia and these all disorders may ultimately lead to metabolic syndrome.