Does hypoadiponectinemia explain the increased risk of diabetes and cardiovascular disease in South Asians?

Diabetes and diabetes care among non-obese South Asian Americans: Findings from a population-based study

AIMS

The aim of this paper is to provide population-based data from California on: (a) the prevalence and the odds of diabetes among non-obese South Asian (SA) Americans compared to non-Hispanic Whites (NHW); (b) to assess the prevalence and odds of optimal medical care including regular eye exams, foot exams, and the monitoring of hemoglobin A1C blood glucose levels; and (c) To identify the factors that are associated with diabetes among SA Americans.

METHODS

The combined 2007, 2009, and 2011 waves of the adult California Health Interview Survey (CHIS) was used to analyze a non-obese (BMI<30) sample of 1251 SA and 72,072 NHW. Chi-square and logistic regression analyses were performed using Stata.

RESULTS

Non-obese SA had more than twice the odds of diabetes in comparison to NHW (OR = 2.50; 1.66, 3.76), even after adjusting for sociodemographic characteristics. Despite their higher propensity for diabetes, there were no significant ethnic differences in the level of optimal care received by those with diabetes. Among non-obese South Asian Americans, the odds of diabetes were higher for older respondents, those without a post-secondary degree, those who were foreign-born, those who had ever smoked, and those with BMI from 25 to 29.99.

CONCLUSIONS

Non-obese SA in California experience a disproportionately higher prevalence of diabetes than their NHW counterparts.

Multi-ethnic comparisons of diabetes in heart failure with reduced ejection fraction: insights from the HF-ACTION trial and the ASIAN-HF registry

AIM

To describe differences in patient characteristics and outcomes by ethnicity in patients with diabetes mellitus (DM) and heart failure (HF) with reduced ejection fraction (HFrEF, ejection fraction ≤35%) in a multi-ethnic cohort.

METHODS AND RESULTS

Patient level data from two cohorts (HF-ACTION and ASIAN-HF) were combined, and patients grouped by self-reported ethnicity. DM was defined as the presence of a clinical diagnosis and/or receiving anti-diabetic therapy. A total of 6214 (1324 whites, 674 blacks, 1297 Chinese, 1510 Indians, 717 Malays, 692 Japanese/Koreans) patients were included. The overall prevalence of DM was 39.5% (n = 2454). The prevalence of DM was lowest in whites (29.3%), followed by Japanese/Koreans (34.1%), blacks (35.9%), Chinese (42.3%), Indians (44.2%), and highest in Malays (51.9%). The correlation between age, sex, body mass index, coronary artery disease, hypertension, atrial fibrillation, peripheral vascular disease and chronic kidney disease with DM differed significantly by ethnicity (P for interaction <0.05). The strongest correlations were seen in Malay women, whites with obesity, Indians with coronary artery disease and hypertension, and blacks with chronic kidney disease. On multivariable analyses, DM was significantly associated with the composite of 1-year overall mortality/HF hospitalization (hazard ratio 1.37, 95% confidence interval 1.19-1.57; P < 0.001), with no interaction by ethnicity (P for interaction =0.31).

CONCLUSIONS

There is marked heterogeneity in the prevalence and correlates of DM among different ethnic groups with HF worldwide. Subgroups particularly predisposed to DM warrant special attention, since DM increases the combined risk of morbidity and mortality in all ethnicities with HF.

Relationship between vitamin D and gestational diabetes in overweight or obese pregnant women may be mediated by adiponectin

SCOPE

Maternal vitamin D deficiency has been implicated in adverse pregnancy outcomes. However, the association between vitamin D and inflammation, particularly adipokines, remains unexplored in pregnancy.

METHODS AND RESULTS

In 102 overweight or obese pregnant women at high-risk of gestational diabetes mellitus (GDM), we investigated relationships between maternal 25-hydroxyvitamin D (25(OH)D) concentrations at 12-15 wk gestation (baseline) and serum lipids, inflammatory markers, novel adipokines (omentin-1, visfatin, high molecular weight (HMW) adiponectin), and subsequent pregnancy outcomes (GDM, preeclampsia, preterm birth [PTB]). After adjustment for maternal factors (age, BMI, parity, ethnicity, and smoking status), baseline 25(OH)D concentrations were inversely associated with total cholesterol and triglycerides, and positively associated with HMW-adiponectin. Higher baseline 25(OH)D concentrations were associated with decreased fasting and 1-h post-OGTT glucose and reduced risk of GDM at 26-28 wk, as well as with longer gestation and reduced risk of PTB upon additional adjustment for caesarean section. Adding HMW-adiponectin to the multivariable models attenuated most associations, and HMW-adiponectin was a significant predictor in the models.

CONCLUSION

Our findings suggest that lower maternal 25(OH)D concentrations in overweight/obese pregnant women at high-risk of GDM are associated with increased cardiometabolic risks during pregnancy and adverse pregnancy outcomes, and that these associations may be mediated by HMW-adiponectin.

Sex hormone-binding globulin and the risk for metabolic syndrome in children of South Asian Indian origin

OBJECTIVE

To determine whether the plasma level of sex hormone-binding globulin (SHBG) identifies South Asian Indian children at risk for metabolic syndrome.

METHODS

Adults and their children aged 5 to 9 years were recruited at the annual health fair at the Hindu temple serving the South Asian Indian community in Louisville, Kentucky. Anthropometric data were collected in adults and children, and blood pressure, lipid, and glucose levels were measured in adults. SHBG levels were measured in children using a fingerstick blood sample. In adults, metabolic syndrome was diagnosed according to the International Diabetes Federation criteria. Twelve months later, follow-up anthropometric data were obtained for a portion of the children.

RESULTS

The study included 30 sets of parents and 30 children. The prevalence of metabolic syndrome among 310 adults attending the health fair was 42% in men and 39% in women. Children with 1 parent with metabolic syndrome had 24% lower SHBG levels that increased to 55% if both parents had metabolic syndrome. SHBG levels were inversely related to waist circumference and to body mass index percentile. Both SHBG and waist circumference predicted weight gain over 1 year in children. CONCLUSIONS Low SHBG levels were found in South Asian Indian children whose parents had attributes of metabolic syndrome. The dose dependency of SHBG is consistent with inheritance of a genetic trait, and if the results are applicable to other racial/ethnic groups, SHBG may be a useful marker to identify at-risk children for early intervention.

Ethnocentric approach to address South Asian health issues

South Asian populations have distinct healthcare requirements to other ethnic demographics. Epidemiologically they constitute a high-risk group for many public health diseases such as cardiovascular disease, chronic kidney disease and diabetes mellitus. Despite individuals of South Asian backgrounds encompassing many individual countries, cultures, religions and backgrounds they share many common health concerns that are poorly tackled in established models of healthcare delivery. To successfully address this burgeoning public health burden, it is important for healthcare professionals and providers to appreciate the need for an ethnocentric approach to South Asian health requirements. Key stakeholders need to understand the need for an integrated ethnocentric approach to challenge the poor health status of this population. Appreciation of the socio-cultural dimension to South Asian healthcare requirements should help guide targeted and focused strategies to improve the outlook for this unique population at high public health risk.

Heart failure among South Asians: a narrative review of risk, nature, outcomes and management

Individuals of South Asian descent have a high prevalence of comorbidities that are risk factors for the development of heart failure (HF), including diabetes mellitus and metabolic syndrome. However, little is known about the prevalence of HF, its management and prognosis for this population compared to Caucasians. Therefore, a literature review relating to the nature, outcome and treatment of HF in South Asian patients compared to Caucasians was conducted. It was anticipated that collating existing studies in this manner would be useful for guiding professionals in managing HF within this ethnic group, given that to achieve optimal care, regimens need to take into account cultural differences that may impact on adherence. Reviewed literature showed that South Asians with HF were more likely to be younger and have diabetes and hypertension. These papers also implied that outcomes for South Asians with HF were similar or even better than for Caucasians. The review highlighted the under-representation of South Asians in HF trials, meaning that evidence-based recommendations tailored to this specific population are limited. This is an important consideration because ethnic differences in response to medication have been reported; it cannot be assumed that treatments shown to work for Caucasians will be efficacious for those from minority ethnic groups.

Role of adipokines and other inflammatory mediators in gestational diabetes mellitus and previous gestational diabetes mellitus

Previous Gestational Diabetes Mellitus (pGDM) is a common condition and has been associated with future development of Type 2 Diabetes Mellitus (T2DM) and Metabolic Syndrome (MS) in women affected. The pathogenesis and risk factors implicated in the development of these conditions later in the lives of women with pGDM are not as yet fully understood. Research has recently focused on a group of substances produced mainly by adipose tissue called adipokines, this group including, among others, adiponectin, leptin, Retinol-Binding Protein-4 (RBP-4), and resistin. These substances as well as other inflammatory mediators (CRP, IL-6, PAI-1, TNF-α) seem to play an important role in glucose tolerance and insulin sensitivity dysregulation in women with pGDM. We summarize the data available on the role of these molecules.

Incidence of diabetes in Asian-Indian subjects: a five year follow-up study from Bangladesh

AIMS

To determine the incidence of Type 2 diabetes and its risk factors. Further, to examine the effect of relative changes in obesity (BMI and waist circumference).

METHODS

A sample of 2011 non-diabetic adults aged 20 and above were randomly selected and followed from 1999 to 2004. Fasting blood glucose including biophysical and anthropometric measures was measured.

RESULTS

The overall 5 year cumulative incidence of diabetes was 16.4 per 1000 person-years and 65.1 per 1000 person-years in those with impaired fasting glucose adjusted for age and sex. Among obesity measures, only waist >85in. increased the risk for diabetes in males (RR=3.0). Relative changes stratified by loss in BMI and WC ≥5% or gain of BMI >15% from the baseline values for men were significantly associated with the incidental cases of diabetes. Increased hip circumference for men was significantly associated with a protective effect while an opposite association was observed for women.

CONCLUSION

Relative change in both loss and excessive gain of BMI were risks for increased diabetes. Targeted intervention in those with impaired fasting blood glucose will expectedly reduce the incidental cases. Further investigations are needed for non obese related diabetes in Asian Indian subjects.

Diabetes in Asia

Prevalence of type 2 diabetes has rapidly increased in native and migrant Asian populations. Diabetes develops at a younger age in Asian populations than in white populations, hence the morbidity and mortality associated with the disease and its complications are also common in young Asian people. The young age of these populations and the high rates of cardiovascular risk factors seen in Asian people substantially increase lifetime risk of cardiovascular disease. Several distinctive features are apparent in pathogenetic factors for diabetes and their thresholds in Asian populations. The economic burden due to diabetes at personal, societal, and national levels is huge. National strategies to raise public awareness about the disease and to improve standard of care and implementation of programmes for primary prevention are urgently needed.

High-molecular weight adiponectin is associated with coronary artery angiographic findings in Asian Indians

Asian Indians (AIs) have a higher prevalence and a more aggressive form of coronary artery disease (CAD), and it has been suggested that hypoadiponectinemia may have a role in this accelerated CAD. The present study was undertaken to determine the extent and severity of angiographic findings in 2 groups of CAD patients matched for age and sex, AIs (n = 29) vs whites (n = 30), and to elucidate the potential relationship between adiponectin (total and high-molecular weight [HMW] form) and the severity and extent of coronary angiographic findings in both groups. Angiographic findings were assessed using the modified Gensini index; and 2 scores, scores 1 and 2, were used to assess the severity and extent. Both Gensini index scores 1 and 2 were higher in the AI group compared with the white group (144.4 +/- 87.1 vs 93.5 +/- 56.3 and 127.2 +/- 86.5 vs 80.1 +/- 39.3, respectively; P < .05). Adiponectin levels were similar in both groups. Total adiponectin and HMW adiponectin were positively associated with Gensini index score 1 (r = 0.62, P = .004 and r = 0.64, P = .003) and score 2 (r = 0.51, P = .021 and r = 0.54, P = .013), respectively, in AI men, whereas there was no significant association in white men. Thus, AIs had more severe CAD compared with whites; and in AI men with CAD, total adiponectin and HMW adiponectin were associated with the severity of angiographic scores.

Association of adiponectin with mortality in older adults: the Health, Aging, and Body Composition Study

AIMS/HYPOTHESIS

Despite inverse associations with insulin resistance and adiposity, adiponectin has been associated with both increased and decreased risk of cardiovascular disease. We examined whether adiponectin is associated with total and cardiovascular mortality in older adults with well-characterised body composition.

METHODS

We analysed data from 3,075 well-functioning adults aged 69-79 years at baseline. Mortality data were obtained over 6.6 +/- 1.6 years. We used Cox proportional hazards models adjusting for covariates in stages to examine the association between adiponectin and total and cardiovascular mortality.

RESULTS

There were 679 deaths, 36% of which were from cardiovascular disease. Unadjusted levels of adiponectin were not associated with total or cardiovascular mortality. However, after adjusting for sex and race, adiponectin was associated with an increased risk of both total mortality (hazard ratio 1.26, 95% CI 1.15-1.37, per SD) and cardiovascular mortality (hazard ratio 1.35, 95% CI 1.17-1.56, per SD). Further adjustment for study site, smoking, hypertension, diabetes, prevalent heart disease, HDL-cholesterol, LDL-cholesterol, renal function, fasting insulin, triacylglycerol, BMI, visceral fat, thigh intermuscular fat and thigh muscle area did not attenuate this association. This association between adiponectin and increased mortality risk did not vary by sex, race, body composition, diabetes, prevalent cardiovascular disease, smoking or weight loss.

CONCLUSIONS/INTERPRETATION

Higher levels of adiponectin were associated with increased risks of total and cardiovascular mortality in this study of older persons.

Plasma adiponectin does not correlate with insulin resistance and cardiometabolic variables in nondiabetic Asian Indian teenagers

OBJECTIVE

The objectives of this study were to determine age- and sex-specific concentrations of adiponectin in Asian Indian teenagers and adults and to assess whether its blood levels correlated with insulin resistance and other cardiometabolic parameters.

RESEARCH DESIGN AND METHODS

We studied 196 teenagers (94 boys, 102 girls) 12-18 years of age, selected from a cohort of 2,640 individuals from a cross-sectional school-based survey in Chennai, India. For comparison, adiponectin and plasma insulin were measured in 84 healthy adults. Correlation of adiponectin with plasma levels of insulin, proinsulin, insulin resistance, anthropometry, and family history of diabetes were studied.

RESULTS

Adiponectin showed a sex dimorphism, with girls having higher values (in microg/ml) (10.3 +/- 5.0) than boys (8.4 +/- 3.5) (P < 0.0001), and it showed a positive correlation with HDL cholesterol in boys only and not with other lipid parameters, insulin resistance, proinsulin, anthropometry, and family history of diabetes. In the adults, adiponectin correlated with fasting glucose and inversely with triglycerides.

CONCLUSIONS

In Asian Indian adults and teenagers, adiponectin did not correlate directly with measures of insulin sensitivity, overweight, and other cardiometabolic variables. This was at variance with several reports in other populations showing an inverse association of adiponectin with insulin resistance, proinsulin, and BMI, suggesting ethnic differences in the relationship of adiponectin with insulin sensitivity. The role of adiponectin in relation to action of insulin needs more detailed studies in Asian Indians.

Adiponectin regulates albuminuria and podocyte function in mice

Increased albuminuria is associated with obesity and diabetes and is a risk factor for cardiovascular and renal disease. However, the link between early albuminuria and adiposity remains unclear. To determine whether adiponectin, an adipocyte-derived hormone, is a communication signal between adipocytes and the kidney, we performed studies in a cohort of patients at high risk for diabetes and kidney disease as well as in adiponectin-knockout (Ad(-/-)) mice. Albuminuria had a negative correlation with plasma adiponectin in obese patients, and Ad(-/-) mice exhibited increased albuminuria and fusion of podocyte foot processes. In cultured podocytes, adiponectin administration was associated with increased activity of AMPK, and both adiponectin and AMPK activation reduced podocyte permeability to albumin and podocyte dysfunction, as evidenced by zona occludens-1 translocation to the membrane. These effects seemed to be caused by reduction of oxidative stress, as adiponectin and AMPK activation both reduced protein levels of the NADPH oxidase Nox4 in podocytes. Ad(-/-) mice treated with adiponectin exhibited normalization of albuminuria, improvement of podocyte foot process effacement, increased glomerular AMPK activation, and reduced urinary and glomerular markers of oxidant stress. These results suggest that adiponectin is a key regulator of albuminuria, likely acting through the AMPK pathway to modulate oxidant stress in podocytes.

Vascular risk factors in South Asians

South Asians originate from the Indian sub-continent (India, Pakistan, Bangladesh, Sri Lanka and Nepal) and represent one fifth of the world's population. Several studies suggested that South Asians have an increased risk of developing coronary heart disease (CHD) when compared with European populations. We review the role of traditional and emerging risk factors in the increased CHD risk in South Asians. The high prevalence of insulin resistance and type 2 diabetes mellitus in South Asians may be a major cause for their elevated vascular risk. However, other established and emerging risk factors are also overrepresented in South Asians. Large-scale prospective studies could determine the relative contribution of established and emerging vascular risk factors in South Asians. There is an urgent need for trials in South Asians that will evaluate clinical outcomes following treatment of these risk factors.

Orlistat in the prevention of diabetes in the obese patient

There has been an increase in the concern about preventing type 2 diabetes mellitus (T2DM), a disease with great and increasing prevalence. The prevalence of obesity, physical inactivity, Western processed diet, important risk factors for the development of T2DM, are also rising. Free fatty acids are increased in obesity and reduce insulin clearance and increase hepatic glucose production. Implementation of a healthy lifestyle has been show to slow the progression of impaired glucose tolerance to T2DM. Orlistat is an inhibitor of lipase activity, with proved efficacy in body weight reduction and long-term management of obesity and more favorable effects on carbohydrate metabolism and it was prospectively shown in XENDOS study that orlistat promoted long-term weight loss and prevented T2DM onset in obese individuals with normal and impaired glucose tolerance at baseline over four years. This benefit could be associated to the weight loss itself, to the limited absorption of lipids and reduction of plasma free fatty acids, to increased production of incretins or to modulation of secretion of cytokines by adipocytes, all effects secondary to orlistat treatment. A proposed strategy is to identify subjects at highest risk to receive a drug intervention, using lifestyle interventions alone at the community level.