HDL cholesterol subfractions and risk of developing type 2 diabetes among Pima Indians

HDL Particle Subspecies and Their Association With Incident Type 2 Diabetes: The PREVEND Study

CONTEXT

High-density lipoproteins (HDL) may be protective against type 2 diabetes (T2D) development, but HDL particles vary in size and function, which could lead to differential associations with incident T2D. A newly developed nuclear magnetic resonance (NMR)-derived algorithm provides concentrations for 7 HDL subspecies.

OBJECTIVE

We aimed to investigate the association of HDL particle subspecies with incident T2D in the general population.

METHODS

Among 4828 subjects of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study without T2D at baseline, HDL subspecies with increasing size from H1P to H7P were measured by NMR (LP4 algorithm of the Vantera NMR platform).

RESULTS

A total of 265 individuals developed T2D (median follow-up of 7.3 years). In Cox regression models, HDL size and H4P (hazard ratio [HR] per 1 SD increase 0.83 [95% CI, 0.69-0.99] and 0.85 [95% CI, 0.75-0.95], respectively) were inversely associated with incident T2D, after adjustment for relevant covariates. In contrast, levels of H2P were positively associated with incident T2D (HR 1.15 [95% CI, 1.01-1.32]). In secondary analyses, associations with large HDL particles and H6P were modified by body mass index (BMI) in such a way that they were particularly associated with a lower risk of incident T2D, in subjects with BMI < 30 kg/m2.

CONCLUSION

Greater HDL size and lower levels of H4P were associated with a lower risk, whereas higher levels of H2P were associated with a higher risk of developing T2D. In addition, large HDL particles and H6P were inversely associated with T2D in nonobese subjects.

Socio-demographic and modifiable risk factors of diabetes and hypertension among resource constrained patients from rural areas in Mdantsane Township in South Africa

Background

Recently, developing countries have shown a dramatic increase in non-communicable diseases (NCDs). The burden of NCDs in South Africa has increased over the past years resulting in an estimated 37% of all- cause mortality and 16% of disability-adjusted life years. Currently, diabetes mellitus (DM) and hypertension (HTN) are the two most prevalent NCDs associated with the rapid increase in mortality.

Objective

To demonstrate the socio-demographic and modifiable risk factors of diabetes mellitus (DM) and hypertension (HTN) among South African adults.

Methods

A cross-sectional analytical study was conducted in the Cecilia Makiwane Hospital serving the residents of Mdantsane. Relevant socio-demographic data, anthropometric measurements, triplicate blood pressure, fasting blood glucose and lipogram analysis were obtained from 265 outpatients.

Results

Multivariate anlysis shows that; salt intake, smoking, elevated triglycerides and decreased high-density lipoprotein levels were significantly associated with DM with adjusted odds ratio of 0.18 (p=0.002), 0.26 (p=0.048), 2.19 (p=0.006) and 0.38 (p=0.001), respectively. Overweight and obesity were significantly associated with hypertension with odds ratio of 0.03 (p=0.01) and 0.06 (p=0.006), respectively.

Conclusion

The burden of DM and HTN on society can be drastically reduced with simple lifestyle changes, development of preventative strategies, large-scale screening and better disease management in South Africa.

Association between lipids and apolipoproteins on type 2 diabetes risk; moderating effects of gender and polymorphisms; the ATTICA study

BACKGROUND AND AIMS

Type 2 diabetes mellitus (T2DM) is a condition defined by hyperglycaemia, but also often presents with dyslipidaemia and suppressed HDL cholesterol. Mendelian randomization studies have suggested a causal link between low HDL cholesterol and T2DM. However, influences of gender, polymorphisms and lifestyle, all known to influence HDL cholesterol, have not been fully explored in a prospective cohort.

METHODS AND RESULTS

In 2001-2002, a random sample of 1514 males (18-87 years old) and 1528 females (18-89 years old) were recruited in the ATTICA study. The 10-year follow-up (2011-2012) included 1485 participants. Lipids and lipoproteins levels, glucose and insulin levels were measured together with apolipoprotein A1 (apoA1) 75 G/A genotype, which is known to influence HDL-cholesterol. In total, 12.9% of the study sample developed T2DM within the 10-year follow-up period. In multivariable models, for each mg/dL increase in apoA1 levels in males, 10-year T2DM risk decreased 1.02%; while every unit increase in apoB/LDL-cholesterol ratio increased risk 4-fold. Finally, for every unit increase in triglycerides/apoA1 ratio, the risk increased 85%. HOMA-IR independently predicted T2DM 10-year incidence only for carriers of GG polymorphism (all, p < 0.05), but not in carriers of the GA polymorphism (all, p > 0.05).

CONCLUSION

ApoA1 was associated with decreased T2DM risk and TG/ApoA1 and apoB/LDL were associated with increased risk of T2DM, only in males. ApoA1 polymorphism, which is associated with lower HDL cholesterol, influenced the predictive effects of HOMA-IR on T2DM incidence, which appeared to be moderated by physical activity, suggesting potential scope for more targeted preventative strategies.

Different inverse association of large high-density lipoprotein subclasses with exacerbation of insulin resistance and incidence of type 2 diabetes: The Nagahama study

AIMS

In addition to its antiatherogenic action, high-density lipoprotein (HDL) may also have an antidiabetes function. Although the biological actions of small HDL (HDL3) and large HDL (HDL2) subclasses may be different, evidence in support of that hypothesis is lacking. The aim of this study was to clarify the difference in prognostic significance of HDL subclasses for exacerbation of insulin resistance and incidence of type 2 diabetes in the general population.

METHODS

Study participants included 8365 community residents 52±13years of age not taking lipid lowering drugs. Serum HDL cholesterol subclasses and low-density lipoprotein subclasses, were measured by a homogeneous assay. Insulin resistance was assessed by homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

Cross-sectional analysis adjusted for possible covariates found that HDL2 cholesterol (HDL2-C) levels were inversely associated with HOMA-IR (β=-0.169, p<0.001), whereas HDL3-C had the opposite association (β=0.054, p<0.001). Similar results were found in an analysis for type 2 diabetes (HDL2-C, odds ratio=0.96, p=0.001; HDL3-C, odds ratio=1.04, p=0.181). In a longitudinal analysis with 5.0years of follow-up, HDL2-C was inversely associated with exacerbation of insulin resistance (β=-0.163, p<0.001); HDL3-C had the opposite association (β=0.026, p=0.037). During follow-up, 205 individuals were newly diagnosed with diabetes, and HDL2-C level was associated with an inverse risk of type 2 diabetes incidence (odds ratio=0.98, p=0.006).

CONCLUSIONS

HDL may have an antidiabetic function; the prognostic value of HDL2-C for diabetes and insulin resistance might be better than that of HDL3-C.

Associations of apolipoprotein B/apolipoprotein A-I ratio with pre-diabetes and diabetes risks: a cross-sectional study in Chinese adults

BACKGROUND

Apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) ratio is a useful predictor of cardiovascular risk. However, the association between the ApoB/ApoA-I ratio and the risk of type 2 diabetes mellitus (T2DM) is still obscure.

AIMS

To investigate the associations between the ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes in a Chinese population, and to assess the role of gender in these associations.

METHODS

A stratified random sampling design was used in this cross-sectional study which included 264 men and 465 women with normal glucose tolerance (NGT), pre-diabetes or T2DM. Serum ApoB, ApoA-I and other lipid and glycaemic traits were measured. Pearson's partial correlation and multivariable logistic analysis were used to evaluate the associations between ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes.

RESULTS

The ApoB/ApoA-I ratios were significantly increased across the spectrum of NGT, pre-diabetes and T2DM. Women showed higher levels of ApoB/ApoA-I ratio and ApoB than men in the pre-diabetic and T2DM groups, but not in the NGT group. The ApoB/ApoA-I ratio was closely related with triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and other glycaemic traits. Moreover, in women, the risk of diabetes and pre-diabetes in the top and middle tertiles of the ApoB/ApoA-I ratio were 3.65-fold (95% CI 1.69 to 6.10) and 2.19-fold (95% CI 1.38 to 2.84) higher than in the bottom tertile, respectively, after adjusting for potential confounding factors. However, the associations disappeared in men after adjusting for other factors.

CONCLUSIONS

The ApoB/ApoA-I ratio showed positive associations with the risk of diabetes and pre-diabetes in Chinese women.

Low Levels of High-Density Lipoprotein Cholesterol Do Not Predict the Incidence of Type 2 Diabetes in an Iranian High-Risk Population: The Isfahan Diabetes Prevention Study

OBJECTIVES

To evaluate the ability of low-level fasting high-density lipoprotein cholesterol (HDLC) to predict the incidence of type 2 diabetes (T2D) in an Iranian high-risk population.

METHODS

Seven-year follow-up data (n = 1,775) in non-diabetic first-degree relatives (FDR) of consecutive patients with T2D aged 30-70 years were analyzed. The primary outcome was the diagnosis of T2D based on repeated oral glucose tolerance test (OGTT). We used Cox proportional hazard models to estimate the hazard ratio (HR) for the incidence of T2D across quartiles of HDLC, and plotted a receiver operating characteristic (ROC) curve to assess discrimination.

RESULTS

The highest quartile compared with the lowest quartile of HDLC was associated with T2D in age- and gender-adjusted models (HR: 0.83, 95% CI: 0.73-0.95). Further adjustment for fasting plasma glucose and cholesterol attenuated the association for T2D incidence (HR: 0.93, 95% CI: 0.80-1.08). The area under the ROC curve for HDLC was 54.1% (95% CI: 50.2-58.0).

CONCLUSIONS

HDLC level was a weak predictor of T2D in an Iranian high-risk population, independent of age and gender.

Subfractions of High-Density Lipoprotein-Cholesterol and Carotid Intima-Media Thickness: The Northern Manhattan Study

BACKGROUND AND PURPOSE

Recent drug trials have challenged the high-density lipoprotein-cholesterol (HDL-C) antiatherosclerotic hypothesis, suggesting that total level of HDL-C may not be the best target for intervention. HDL-C subfractions may be better markers of vascular risk than total levels of HDL-C. The objective of this cross-sectional study was to investigate the relationship between HDL2-C and HDL3-C fractions and carotid intima-media thickness (cIMT) in the population-based Northern Manhattan Study.

METHODS

We evaluated 988 stroke-free participants (mean age, 66±8 years; 60% women; 66% Hispanic, and 34% non-Hispanic) with available data on HDL-C subfractions using precipitation method and cIMT assessed by a high-resolution carotid ultrasound. The associations between HDL-C subfractions and cIMT were analyzed by multiple linear regression models.

RESULTS

The mean HDL2-C was 14±8 mg/dL, HDL3-C 32±8 mg/dL, and the mean total HDL-C was 46±14 mg/dL. The mean cIMT was 0.90±0.08 mm. After controlling for demographics and vascular risk factors, HDL2-C and total HDL-C were inversely associated with cIMT (per 2 SDs, β=-0.017, P=0.001 and β=-0.012, P=0.03, respectively). The same inverse association was more pronounced among those with diabetes mellitus (per 2SDs, HDL2-C: β=-0.043, P=0.003 and HDL-C: β=-0.029, P=0.02). HDL3-C was not associated with cIMT.

CONCLUSIONS

HDL2-C had greater effect on cIMT than HDL3-C in this large urban population. The effect of HDL2-C was especially pronounced among individuals with diabetes mellitus. More research is needed to determine antiatherosclerotic effects of HDL-C subfractions and their clinical relevance.

Assessment of established HDL-C loci for association with HDL-C levels and type 2 diabetes in Pima Indians

AIMS/HYPOTHESIS

Epidemiological studies in Pima Indians identified elevated levels of HDL-cholesterol (HDL-C) as a protective factor against type 2 diabetes risk in women. We assessed whether HDL-C-associated single-nucleotide polymorphisms (SNPs) also associate with type 2 diabetes in female Pima Indians.

METHODS

Twenty-one SNPs in established HDL-C loci were initially analysed in 2,675 full-heritage Pima Indians. SNPs shown to associate with HDL-C (12 SNPs) were assessed for association with type 2 diabetes in 7,710 Pima Indians (55.6% female sex). The CETP locus provided the strongest evidence for association with HDL-C and was further interrogated by analysing tag SNPs.

RESULTS

Twelve of the 21 SNPs analysed had a significant association with HDL-C in Pima Indians; five SNPs representing four loci (CETP, DOCK6, PPP1R3B and ABCA1) reached genome-wide significance. Three SNPs, at CETP, KLF14 and HNF4A, associated with type 2 diabetes only in female participants with the HDL-C-lowering allele increasing diabetes risk (p values: 3.2 × 10(-4) to 7.7 × 10(-5)); the association remained significant even after adjustment for HDL-C. Additional analysis across CETP identified rs6499863 as having the strongest association with type 2 diabetes in female participants (p = 5.0 × 10(-6)) and this association remained independent of the HDL-C association.

CONCLUSIONS/INTERPRETATION

SNPs at the CETP, HNF4A and KLF14 locus are associated with HDL-C levels and type 2 diabetes (in female participants). However, since HNF4A and KLF14 are established loci for type 2 diabetes, it is unlikely that HDL-C solely mediates these associations.

Differential Association Between HDL Subclasses and the Development of Type 2 Diabetes in a Prospective Study of Japanese Americans

OBJECTIVE

Recent studies have suggested that HDL cholesterol is inversely associated with the development of type 2 diabetes. However, little is known about the association between different HDL subclasses and the risk for future type 2 diabetes.

RESEARCH DESIGN AND METHODS

The study enrolled 406 Japanese Americans (51% male) without diabetes, aged 34-75 years. Oral glucose tolerance tests were performed to determine type 2 diabetes status at baseline, 2.5 years, 5 years, and 10 years after enrollment. HDL2, HDL3, total HDL cholesterol, and visceral adipose tissue (VAT) area by computed tomography were measured at baseline.

RESULTS

In univariate analysis, total HDL and HDL2 cholesterol were inversely associated with the incidence of type 2 diabetes, but HDL3 cholesterol was not. In multivariate analysis, total HDL cholesterol (odds ratio per 1-SD increment, 0.72 [95% CI 0.52-0.995], P = 0.047) and HDL2 cholesterol (odds ratio per 1-SD increment, 0.64 [95% CI 0.44-0.93], P = 0.018) were inversely associated with the risk for type 2 diabetes independent of age, sex, BMI, waist circumference, family history of diabetes, lifestyle factors, systolic blood pressure, lipid-lowering medication use, triglyceride level, HOMA-insulin resistance, and 2-h glucose; however, HDL3 cholesterol was not associated with diabetes risk. The association between diabetes risk and total HDL and HDL2 cholesterol became insignificant after adjustment for VAT area.

CONCLUSIONS

Subjects with higher HDL2 cholesterol were at lower risk for incident type 2 diabetes, but this association was confounded by and not independent of VAT. Higher HDL3 cholesterol was not associated with diabetes risk.

Associations of multiple lipoprotein and apolipoprotein measures with worsening of glycemia and incident type 2 diabetes in 6607 non-diabetic Finnish men

OBJECTIVE

We investigated the association of various lipoprotein traits, apolipoproteins and their ratios with the deterioration of glycemia, incident type 2 diabetes, insulin resistance and insulin secretion in a large population-based Metabolic Syndrome Men (METSIM) Study.

RESEARCH DESIGN AND METHODS

The METSIM Study includes 10,197 Finnish men, aged 45-73 years, and examined in 2005-2010. From 6607 non-diabetic participants without statin treatment at baseline, 386 developed incident type 2 diabetes during a 5.9-year follow-up. A total of 3330 non-diabetic participants without statin treatment had both baseline and follow-up visit data, and were included in statistical analyses of the worsening of glycemia.

RESULTS

Compared to single lipid and lipoprotein measurements, lipoprotein and apolipoprotein ratios were better predictors of the glucose area under the curve and incident type 2 diabetes after adjustment for confounding factors. The apolipoprotein B/LDL cholesterol ratio was the strongest predictor of the worsening of glycemia, whereas the apolipoprotein A1/HDL cholesterol ratio was the strongest predictor of incident type 2 diabetes. The associations of lipoprotein traits, apolipoproteins and their ratios with insulin sensitivity were stronger than those with insulin secretion.

CONCLUSIONS

The apolipoprotein B/LDL cholesterol and apolipoprotein A1/HDL cholesterol ratios were the strongest predictors of the worsening of glycemia and incident type 2 diabetes, respectively.

High-density lipoprotein subfractions and carotid plaque: the Northern Manhattan Study

OBJECTIVE

The objective of this cross-sectional analysis was to investigate the relation between two major high-density lipoprotein cholesterol (HDL-C) subfractions (HDL2-C and HDL3-C) and carotid plaque in a population based cohort.

METHODS

We evaluated 988 stroke-free participants (mean age 66 ± 8 years; 40% men; 66% Hispanic and 34% Non-Hispanic) with available data on HDL subfractions using precipitation method and carotid plaque area and thickness assessed by a high-resolution 2D ultrasound. The associations between HDL-C subfractions and plaque measurements were analyzed by quantile regression.

RESULTS

Plaque was present in 56% of the study population. Among those with plaque, the mean ± SD plaque area was 19.40 ± 20.46 mm² and thickness 2.30 ± 4.45 mm. The mean ± SD total HDL-C was 46 ± 14 mg/dl, HDL2-C 14 ± 8 mg/dl, and HDL3-C 32 ± 8 mg/dl. After adjusting for demographics and vascular risk factors, there was an inverse association between HDL3-C and plaque area (per mg/dl: beta = -0.26 at the 75th percentile, p = 0.001 and beta = -0.32 at the 90th percentile, p = 0.02). A positive association was observed between HDL2-C and plaque thickness (per mg/dl; beta = 0.02 at the 90% percentile, p = 0.003). HDL-C was associated with plaque area (per mg/dl: beta = -0.18 at the 90th percentile, p = 0.01), but only among Hispanics.

CONCLUSION

In our cohort we observed an inverse association between HDL3-C and plaque area and a positive association between HDL2-C and plaque thickness. HDL-C subfractions may have different contributions to the risk of vascular disease. More studies are needed to fully elucidate HDL-C anti-atherosclerotic functions in order to improve HDL-based treatments in prevention of vascular disease and stroke.

Metabolic syndrome components and their response to lifestyle and metformin interventions are associated with differences in diabetes risk in persons with impaired glucose tolerance

AIMS

To determine the association of metabolic syndrome (MetS) and its components with diabetes risk in participants with impaired glucose tolerance (IGT), and whether intervention-related changes in MetS lead to differences in diabetes incidence.

METHODS

We used the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) revised MetS definition at baseline and intervention-related changes of its components to predict incident diabetes using Cox models in 3234 Diabetes Prevention Program (DPP) participants with IGT over an average follow-up of 3.2 years.

RESULTS

In an intention-to-treat analysis, the demographic-adjusted hazard ratios (95% confidence interval) for diabetes in those with MetS (vs. no MetS) at baseline were 1.7 (1.3-2.3), 1.7 (1.2-2.3) and 2.0 (1.3-3.0) for placebo, metformin and lifestyle groups, respectively. Higher levels of fasting plasma glucose and triglycerides at baseline were independently associated with increased risk of diabetes. Greater waist circumference (WC) was associated with higher risk in placebo and lifestyle groups, but not in the metformin group. In a multivariate model, favourable changes in WC (placebo and lifestyle) and high-density lipoprotein cholesterol (placebo and metformin) contributed to reduced diabetes risk.

CONCLUSIONS

MetS and some of its components are associated with increased diabetes incidence in persons with IGT in a manner that differed according to DPP intervention. After hyperglycaemia, the most predictive factors for diabetes were baseline hypertriglyceridaemia and both baseline and lifestyle-associated changes in WC. Targeting these cardiometabolic risk factors may help to assess the benefits of interventions that reduce diabetes incidence.

Role of HDL cholesterol and estimates of HDL particle composition in future development of type 2 diabetes in the general population: the PREVEND study

BACKGROUND AND AIMS

High-density lipoproteins (HDLs) may directly stimulate β-cell function and glucose metabolism. We determined the relationships of fasting high-density lipoprotein cholesterol (HDL-C), plasma apolipoprotein (apo) A-I and apoA-II, and HDL-C-to-apoA-I and HDL-C-to-apoA-II ratios, as estimates of HDL particle composition, with incident type 2 diabetes mellitus.

METHODS

A prospective study was carried out in the Prevention of Renal and Vascular End-Stage Disease (PREVEND) cohort after exclusion of subjects with diabetes at baseline (n = 6820; age, 28-75 years). The association of HDL-related variables with incident type 2 diabetes was determined by multivariate logistic regression analyses.

RESULTS

After a median follow-up of 7.7 years, 394 incident cases of type 2 diabetes mellitus were ascertained (5.8%). After adjustment for age, sex, family history of diabetes, body mass index, hypertension, alcohol, and smoking, odd ratios (ORs) for diabetes were 0.55 (95% confidence interval [CI], 0.47-0.64; P < .001), 0.81 (0.71-0.93; P = .002), 0.02 (0.01-0.06; P < .001), and 0.03 (0.01-0.060; P < .001) per 1-SD increase in HDL-C and apoA-I and in the HDL-C-to-apoA-I and the HDL-C-to-apoA-II ratios, respectively. In contrast, apoA-II was not related to incident diabetes (OR = 1.02; 95% CI, 0.90-1.16; P=0.71). The relationships of HDL-C and the ratios of HDL-C to apoA-I and HDL-C to apoA-II remained significant after further adjustment for baseline glucose and triglycerides (OR(HDL) = 0.74 [95% CI, 0.61-0.88], OR(HDL/APO A-I) = 0.14 [0.04-0.44], and OR(HDL/APOA-II) = 0.12 [0.04-0.36]; all P ≤ .001).

CONCLUSIONS

Higher HDL-C, as well as higher HDL-C-to-apoA-I and HDL-C-to-apoA-II ratios are strongly and independently related to a lower risk of future type 2 diabetes.

Sex differences in HDL ApoC-III in American Indian youth

Background

Since American Indians are predisposed to type 2 diabetes (DM2) and associated cardiovascular risk, Cherokee boys and girls (n = 917) were studied to determine whether BMI Z (body mass index Z score) is associated with the apoC-III (apolipoprotein C-III) content of HDL (high density lipoprotein), a previously reported predictor of DM2.

Methods

An ad hoc cross-sectional analysis was conducted on a previously studied cohort. Participants were grouped by gender-specific age groups (5 to 9, 10 to 14 and 15 to 19 years). ApoA-I (apolipoprotein A-I) and HDL apoC-III were assayed by electroimmunoassay. ApoC-III was measured in whole plasma, and in HDL to determine the molar proportion to apoA-I. General linear models were used to assess association.

Results

The HDL apoC-III to apoA-I molar ratio increased by BMI Z quartile in girls aged 10–14 years (p < 0.05 for linear trend, p < 0.05 for difference in BMI Z quartile IV vs. I to III) and aged 15–19 years (p < 0.05 for trend). In boys the increase by BMI Z occurred only at ages 15–19 years (p < 0.01 for trend and for quartile difference).

Conclusions

ApoC-III showed an obesity-related increase relative to apoA-I during adolescence beginning in girls aged 10 to 14 years and in boys aged 15 to 19 years. The earlier changes in girls may alter HDL’s protective properties on the β-cell and contribute to their increased risk for DM2.

The emerging role of HDL in glucose metabolism

A low plasma level of HDL cholesterol is an atherosclerotic risk factor; however, emerging evidence suggests that low HDL levels might also contribute to the pathophysiology of type 2 diabetes mellitus (T2DM) through direct effects on plasma glucose. In the past decade, animal and clinical studies have uncovered a previously undescribed spectrum of HDL actions, indicating that HDL may control glucose homeostasis through mechanisms including insulin secretion, direct glucose uptake by muscle via the AMP-activated protein kinase, and possibly enhanced insulin sensitivity. These effects are mediated by multiple cell types via mechanisms including preservation of cell function through cellular lipid removal and also via direct signaling events. We suggest a paradigm shift from HDL being a bystander to being an active player in diabetic pathophysiology, which raises the possibility that HDL elevation could be a novel therapeutic avenue for T2DM. The entry of HDL-raising agents of the cholesteryl ester transfer protein (CETP) inhibitor class into late-phase clinical trials creates potential for rapid clinical translation. This Review will discuss the emerging evidence for a role of HDL-mediated glucose regulation in the pathophysiology of T2DM, and will also outline the therapeutic potential for HDL elevation for the prevention and management of T2DM.

A case-control study on the relationship between HDL2b and non-alcoholic fatty liver disease in Chinese type 2 diabetic patients

BACKGROUND

It has been shown that low concentrations of high-density lipoprotein cholesterol (HDL-C) are associated with non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). HDL2b, a major subfraction of high-density lipoprotein (HDL), is more significantly correlated with coronary heart disease (CHD) compared with total HDL. In this study, we analysed HDL2b in a cohort of Chinese T2DM subjects with or without NAFLD.

METHODS

A highly sensitive and reliable microfluidic chip method was adopted to measure HDL2b. In total, 48 T2DM patients with NAFLD diagnosed by a B-ultrasound were enrolled from our Beijing Community Pre-Diabetes (BCPD) study cohort. A total of 48 age and gender matched diabetic controls without NAFLD were selected from the same population.

RESULTS

Clinical characteristics and serum biochemical analyses demonstrated a significantly increased body mass index (BMI), waist circumference, homeostasis model assessment-insulin resistant index (HOMA-IR), total cholesterol (TC), and triglyceride (TG) concentrations in the NAFLD group. However, the concentrations of HDL2b and its ratio to total HDL in NAFLD patients was decreased, compared with controls (p<0.01). Significantly increased concentrations of high sensitive C-reactive protein (hs-CRP) (p<0.01) were also found. Multifactor logistic regression analysis showed that BMI and TG were the predominant risk factors for fatty liver, while HDL2b was a protective factor.

CONCLUSIONS

T2DM patients with NAFLD have characteristics including obesity, marked insulin resistance, high TG, high hs-CRP, low HDL2b and a low HDL2b ratio to total HDL. These factors may increase the incidence of atherosclerosis as well as the risk of CHD.

Low fasting triglycerides: hallmark of the healthy large hip?

Body fat distribution modulates risk for type 2 diabetes mellitus. We evaluated potentially involved metabolic risk factors. In a population of 282 male and 157 female healthy subjects (data from the San Antonio and the European Group of Insulin Resistance (EGIR) study cohorts), we evaluated associations between body fat distribution (assessed by waist and hip circumference) and parameters of lipid- and glucose metabolism, including clamp measurements of insulin sensitivity. After stratification for BMI, fasting triglycerides were lower in the presence of a large hip, and higher in a large waist. Persons with the largest BMI (3rd tertile) showed a difference in triglyceride levels of 1.5 vs. 2.4 mmol/l in large vs. small hip circumference groups (P < 0.038), and a difference of 1.5 vs. 1.2 mmol/l in large vs. small waist circumference groups (P < 0.025). A similar analysis did not reveal a difference in insulin sensitivity. Linear regression analyses confirmed the findings; they revealed negative associations between triglycerides and hip, and (for women borderline statistically significant) positive associations between triglycerides and waist, after adjustment for BMI, mutual confounding, and age (beta +/- s.e.; men: -0.48 +/- 0.005, P < 0.001, and 0.21 +/- 0.005, P < 0.05; women: -0.78 +/- 0.007, P < 0.001, and 0.24 +/- 0.005, P < 0.065), respectively. Linear regression analyses revealed similar opposite associations with high-density lipoprotein (HDL)-cholesterol, though not with glucose, insulin, or insulin sensitivity as measured with the clamp method. In our study population of healthy persons, body fat distribution is associated with fasting triglycerides and HDL-cholesterol, and not with insulin sensitivity. Metabolic risk of unfavorable body fat distribution may be modulated by lower triglyceride storage capacity.

Carbohydrate intake and incidence of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study

It remains unclear what long-term effects of substituting carbohydrates at the expense of protein or fat may have with regard to diabetes risk. Our objective was to evaluate carbohydrate intake in predicting type 2 diabetes using substitution models for fat and protein. We conducted a prospective cohort study of 9,702 men and 15,365 women aged 35-65 years and free of diabetes at baseline (1994-8) who were followed for incident type 2 diabetes until 2005. Dietary intake of macronutrients was estimated with a validated FFQ. We estimated the relative risk (RR) using Cox proportional hazards analysis. During 176,117 person-years of follow-up we observed 844 incident cases of physician-confirmed type 2 diabetes. After adjustment for age, BMI, waist circumference, potential lifestyle and dietary confounders, substituting 5 % of energy intake from total, saturated, or monounsaturated fat with carbohydrates was not associated with diabetes risk. In contrast, substituting carbohydrates for protein or PUFA was inversely related to diabetes risk (RR for 5 % energy substitution of protein 0.77 (95 % CI 0.64, 0.91); RR for PUFA 0.83 (95 % CI 0.70, 0.98)). These associations appeared to be similar for men and women, but gained statistical significance only among men for protein (RR 0.78 (95 % CI 0.61, 0.99)). Restricted cubic spline regression did not indicate non-linearity of these associations (P for non-linearity in full cohort was 0.353 and 0.349). In conclusion, a higher carbohydrate intake at the expense of protein and PUFA might be associated with decreased diabetes risk.

Comorbidity of Alcohol Abuse and Dependence with Medical Conditions in 2 American Indian Reservation Communities

BACKGROUND

The objective was to examine the association of self-reported Diagnostic and Statistical Manual-IV edition alcohol abuse and dependence with medical conditions among American Indians (AIs).

METHODS

We analyzed data previously collected in a large epidemiological study of members of 2 culturally distinct AI tribes from the Southwest (SW; n = 1,446) and the Northern Plains (NP; n = 1,638) living on or near their reservations. Associations of combined self-reported alcohol abuse and alcohol dependence with 19 medical conditions were examined through multinomial logistic regression.

RESULTS

Medical conditions that had significant relationships with alcohol abuse/dependence were sprains and strains [odds ratio (OR) 2.04, p < 0.001], hearing and vision problems (OR 2.05, p < 0.001), kidney and bladder problems (OR 1.55, p < 0.01), head injuries (OR 2.20, p < 0.001), pneumonia/tuberculosis (OR 1.49, p < 0.01), dental problems (OR 1.89, p < 0.001), and liver problems/pancreatitis (OR 2.18, p < 0.001). The total count of medical conditions was also significantly related to alcohol abuse/dependence, with a higher count being associated with the outcome (OR 1.17, p < 0.001).

CONCLUSIONS

In this community-based study of rural AIs, diverse medical conditions were associated with alcohol abuse and dependence. Further research should examine, and confirm, the nature, extent, and tribal variation of the medical consequences of alcohol abuse and dependence in these unique populations.

Moderate alcohol consumption lowers the risk of type 2 diabetes: a meta-analysis of prospective observational studies

OBJECTIVE

This meta-analysis was undertaken to obtain insight regarding the shape and strength of the relationship between alcohol consumption and the risk of type 2 diabetes, the effects of adjustment for confounders, and the effect of modification by type 2 diabetes definition, sex, and BMI.

RESEARCH DESIGN AND METHODS

The 15 original prospective cohort studies that were included comprise 11,959 incident cases of type 2 diabetes in 369,862 individuals who, on average, were followed for 12 years.

RESULTS

After pooling the data, a U-shaped relationship was found. Compared with nonconsumers, the relative risk (RR) for type 2 diabetes in those who consumed </=6 g/day alcohol was 0.87 (95% CI 0.79-0.95). For the moderate consumption ranges of 6-12, 12-24, and 24-48 g/day, RRs of 0.70 (0.61-0.79), 0.69 (0.58-0.81), and 0.72 (0.62-0.84) were found, respectively. The risk of type 2 diabetes in heavy drinkers (>/=48 g/day) was equal to that in nonconsumers (1.04 [0.84-1.29]). In general, nonsignificant trends for larger RR reduction associated with moderate alcohol consumption were observed for women compared with men, for crude compared with multivariate-adjusted analyses, and for studies that used self-reports instead of testing for type 2 diabetes definition. No differences in RR reductions were found between individuals with low or high BMI.

CONCLUSIONS

The present evidence from observational studies suggests an approximately 30% reduced risk of type 2 diabetes in moderate alcohol consumers, whereas no risk reduction is observed in consumers of >/=48 g/day.