Plasma lipoproteins and incidence of non-insulin-dependent diabetes mellitus in Pima Indians: protective effect of HDL cholesterol in women

Type 2 diabetes in children and adolescents: distinct characteristics and evidence-based management

PURPOSE

Since the dramatic rise of obesity prevalence in childhood and adolescence has contributed to increased rates of type 2 diabetes (T2D) in youth, we sought to explore current evidence-based management options for pediatric T2D patients.

METHODS

A comprehensive literature search was performed for studies of T2D in childhood and adolescence until September 2021.

RESULTS

Special pathophysiological and diagnostic characteristics of T2D in this age are presented, while the main focus of the article is on management. Lifestyle interventions with healthy diet and exercise are of great importance for the treatment of T2D in children and adolescents. Metformin and insulin remain the traditional therapeutical means, while liraglutide recently gained indication for children older than 10 years both in USA and Europe. Data on the use, efficacy, safety and therapeutic considerations of other pharmacological treatments in children and adolescents with T2D are critically discussed.

CONCLUSION

Although many new and promising therapeutic strategies have been introduced during recent years for the management of T2D in adults, available therapeutic options for the management of pediatric T2D remain limited.

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.

High-Density Lipoprotein Particles and Their Relationship to Posttransplantation Diabetes Mellitus in Renal Transplant Recipients

High concentrations of high-density lipoprotein (HDL) cholesterol are likely associated with a lower risk of posttransplantation diabetes mellitus (PTDM). However, HDL particles vary in size and density with yet unestablished associations with PTDM risk. The aim of our study was to determine the association between different HDL particles and development of PTDM in renal transplant recipients (RTRs). We included 351 stable outpatient adult RTRs without diabetes at baseline evaluation. HDL particle characteristics and size were measured by nuclear magnetic resonance (NMR) spectroscopy. During 5.2 (IQR, 4.1‒5.8) years of follow-up, 39 (11%) RTRs developed PTDM. In multivariable Cox regression analysis, levels of HDL cholesterol (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.40-0.94 per 1SD increase; p = 0.024) and of large HDL particles (HR 0.68, 95% CI 0.50-0.93 per log 1SD increase; p = 0.017), as well as larger HDL size (HR 0.58, 95% CI 0.36-0.93 per 1SD increase; p = 0.025) were inversely associated with PTDM development, independently of relevant covariates including, age, sex, body mass index, medication use, transplantation-specific parameters, blood pressure, triglycerides, and glucose. In conclusion, higher concentrations of HDL cholesterol and of large HDL particles and greater HDL size were associated with a lower risk of PTDM development in RTRs, independently of established risk factors for PTDM development.

ShinyGPA: An interactive visualization toolkit for investigating pleiotropic architecture using GWAS datasets

In spite of accumulating evidence suggesting that different complex traits share a common risk basis, namely pleiotropy, effective investigation of pleiotropic architecture still remains challenging. In order to address this challenge, we developed ShinyGPA, an interactive and dynamic visualization toolkit to investigate pleiotropic structure. ShinyGPA requires only the summary statistics from genome-wide association studies (GWAS), which reduces the burden on researchers using this tool. ShinyGPA allows users to effectively investigate genetic relationships among phenotypes using a flexible low-dimensional visualization and an intuitive user interface. In addition, ShinyGPA provides joint association mapping functionality that can facilitate biological understanding of the pleiotropic architecture. We analyzed GWAS summary statistics for 12 phenotypes using ShinyGPA and obtained visualization results and joint association mapping results that are well supported by the literature. The visualization produced by ShinyGPA can also be used as a hypothesis generating tool for relationships between phenotypes, which might also be used to improve the design of future genetic studies. ShinyGPA is currently available at https://dongjunchung.github.io/GPA/.

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.

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.

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.

In-treatment HDL cholesterol levels and development of new diabetes mellitus in hypertensive patients: the LIFE Study

AIMS

Although hypertensive patients with low baseline HDL cholesterol levels have a higher incidence of diabetes mellitus, whether changing levels of HDL over time are more strongly related to the risk of new diabetes in hypertensive patients has not been examined.

METHODS

Incident diabetes mellitus was examined in relation to baseline and in-treatment HDL levels in 7485 hypertensive patients with no history of diabetes randomly assigned to losartan- or atenolol-based treatment.

RESULTS

During 4.7 ± 1.2 years follow-up, 520 patients (6.9%) developed new diabetes. In univariate Cox analyses, compared with the highest quartile of HDL levels (> 1.78 mmol/l), baseline and in-treatment HDL in the lowest quartile (< 1.21 mmol/l) identified patients with > 5-fold and > 9 fold higher risks of new diabetes, respectively; patients with baseline or in-treatment HDL in the 2nd and 3rd quartiles had intermediate risk of diabetes. In multivariable Cox analyses, adjusting for randomized treatment, age, sex, race, prior anti-hypertensive therapy, baseline uric acid, serum creatinine and glucose entered as standard covariates, and in-treatment non-HDL cholesterol, Cornell product left ventricular hypertrophy, diastolic and systolic pressure, BMI, hydrochlorothiazide and statin use as time-varying covariates, the lowest quartile of in-treatment HDL remained associated with a nearly 9-fold increased risk of new diabetes (hazard ratio 8.7, 95% CI 5.0-15.2), whereas the risk of new diabetes was significantly attenuated for baseline HDL < 1.21 mmol/l (hazard ratio 3.9, 95% CI 2.8-5.4).

CONCLUSIONS

Lower in-treatment HDL is more strongly associated with increased risk of new diabetes than baseline HDL level.

Racial and ethnic differences in cardio-metabolic risk in individuals with undiagnosed diabetes: National Health and Nutrition Examination Survey 1999-2008

BACKGROUND

Although early recognition and treatment of diabetes may be essential to prevent complications, roughly one-fifth of diabetes remains undiagnosed.

OBJECTIVE

Examine cardio-metabolic risk factors and their control in non-Hispanic white (NHW), non-Hispanic black (NHB) and Mexican American (MA) individuals with undiagnosed diabetes.

DESIGN

Nationally representative cross-sectional study of participants in the National Health and Nutrition Examination Survey (NHANES) continuous cycles conducted 1999 through 2008.

PARTICIPANTS

Of 22,621 non-pregnant individuals aged ≥20 years, 2521 had diagnosed diabetes. Of the remaining 20,100 individuals, 17,963 had HbA1c measured, 551 of whom were classified as having undiagnosed diabetes and comprise the study population.

MAIN MEASURES

Undiagnosed diabetes was defined as HbA1c ≥ 6.5% without a self-report of physician diagnosed diabetes. Cardio-metabolic risk factor control was examined using regression methods for complex survey data.

KEY RESULTS

Among individuals with undiagnosed diabetes, mean HbA1c level was 7.7% (95% CI: 7.5, 7.9), 19.3% (95% CI: 14.2, 24.3) smoked, 59.7% (95% CI: 54.5, 64.8%) had hypertension and 96.5% (95% CI: 94.6, 98.4%) had dyslipidemia. Lipid profiles were remarkably different across racial-ethnic groups: NHB had the highest LDL- and HDL-cholesterol, but the lowest triglycerides, while MA had the highest triglycerides and the lowest LDL-cholesterol. After adjusting for age, sex, NHANES examination cycle and use of either blood pressure or lipid medication, the odds of having blood pressure ≥130/80 mmHg was higher in NHB [1.92 (95% CI: 1.09, 3.55)] than NHW, while the odds of having LDL-cholesterol >100 mg/dl was higher in NHW[2.93 (95% CI: 1.37, 6.24)] and NHB[3.34 (95% CI: 1.08, 10.3)] than MA.

CONCLUSIONS

In a nationally representative sample of individuals with undiagnosed diabetes, cardio-metabolic risk factor levels were high across all racial/ethnic groups, but NHB and MA had poorer control compared to NHW. Interventions that target identification of diabetes and treatment of cardio-metabolic risk factors are needed.

Incidence of and risk factors for type-2 diabetes in a general population: The Tromsø Study

Aims: To determine the gender-specific incidence and risk factors of type-2 diabetes mellitus (T2DM) in a general population. Methods: The study is based on 12,431 men and 13,737 women aged 25-98 years, attending the Tromsø Study in 1994 and followed through 2005, who did not have diabetes when entering the study. Sex-specific hazard ratios were estimated from Cox proportional hazard models. Results: A total of 522 cases of T2DM were registered, 308 among men and 214 among women. The age-standardised incidence rate was higher in men than in women, 2.6 (95% CI 2.32—2.90) and 1.6 (95% CI 1.40—1.83) per 1000 person-years, respectively. In multivariate survival analysis, age, body mass index (BMI), triglycerides, high-density lipoprotein (HDL) cholesterol, hypertension, family history of diabetes, low education and smoking were independent predictors of T2DM in both genders (p>0.05). Total cholesterol and lack of leisure-time physical activity were independent predictors in men only. We found an interaction between HDL cholesterol and triglyceride levels (p>0.001) and between triglyceride levels and a positive family history of diabetes (p = 0.04). These interactions were independent of BMI. A positive family history combined with triglycerides in the highest tertile and BMI >25 kg/m2 conveyed a 10-year risk of T2DM of 10% (95% CI 8—12%) vs. 0.2% (95% CI 0.08—0.31%) for the lowest risk group. Conclusions: A family history of diabetes, elevated BMI, and high triglyceride levels identifies independent of cardiovascular risk factors, a group with especially high risk of T2DM.

A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans

It has been suggested that the higher susceptibility of Hispanics to metabolic disease is related to their Native American heritage. A frequent cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) gene variant (R230C, rs9282541) apparently exclusive to Native American individuals was associated with low high-density lipoprotein cholesterol (HDL-C) levels, obesity and type 2 diabetes in Mexican Mestizos. We performed a more extensive analysis of this variant in 4405 Native Americans and 863 individuals from other ethnic groups to investigate genetic evidence of positive selection, to assess its functional effect in vitro and to explore associations with HDL-C levels and other metabolic traits. The C230 allele was found in 29 of 36 Native American groups, but not in European, Asian or African individuals. C230 was observed on a single haplotype, and C230-bearing chromosomes showed longer relative haplotype extension compared with other haplotypes in the Americas. Additionally, single-nucleotide polymorphism data from the Human Genome Diversity Panel Native American populations were enriched in significant integrated haplotype score values in the region upstream of the ABCA1 gene. Cells expressing the C230 allele showed a 27% cholesterol efflux reduction (P< 0.001), confirming this variant has a functional effect in vitro. Moreover, the C230 allele was associated with lower HDL-C levels (P = 1.77 x 10(-11)) and with higher body mass index (P = 0.0001) in the combined analysis of Native American populations. This is the first report of a common functional variant exclusive to Native American and descent populations, which is a major determinant of HDL-C levels and may have contributed to the adaptive evolution of Native American populations.

The relationship of glycaemic control and triglycerides in patients with diabetes mellitus: a PreCIS Database Study

AIMS

A common therapeutic approach in patients with type 2 diabetes mellitus who have elevated triglycerides (TGs) is to treat the hyperglycaemia before specifically targeting high TG. The aims of the current study were (i) to determine whether there was a relationship between glycated haemoglobin (HgbA1c) and TG levels at the baseline visit and (ii) to analyse the relationship between DeltaHgbA1c and DeltaTG after treatment.

METHODS

Among 650 consecutive diabetic patients seen in the Cleveland Clinic Preventive Cardiology Department, 372 had both baseline and post-treatment HgbA1c and TG values. We analysed the relationship between baseline HgbA1c and TG as well as between the change in HgbA1c and the change in TG. For analysis, patients were divided into nine groups by tertiles of HgbA1c (< or =6.6, 6.7-7.8 and >7.8%) and TG (< or =1.75, 1.76-3.89 and >3.89 mmol/l) at baseline.

RESULTS

At baseline, there was a small correlation between HgbA1c and TG (r(2) = 0.051; p < 0.001). For the entire group, there was a significant correlation between DeltaHgbA1c and DeltaTG from baseline to follow-up (r(2) = 0.077; p < 0.001). Analyses by tertiles showed that DeltaTG were only associated with changes in two groups: HgbA1c tertile 3 (>7.8%) and TG tertiles 2 (r(2) = 0.24; p < 0.0001) and 3 (r(2) = 0.187; p = 0.003). For every 1% change in the top tertile HgbA1c, there was a 9.3% change in TG (tertile 2) and a 9.8% change in TG (tertile 3).

CONCLUSIONS

These observations suggest that for patients with diabetes mellitus and elevated TG, the effect of HgbA1c reduction has limited effects on TG reduction. Patients may benefit from TG-specific therapy initiated earlier rather than waiting to see effects of glycaemic control.

Higher prevalence of risk factors for type 2 diabetes mellitus and subsequent higher incidence in men

BACKGROUND

This study investigates risk factors and the incidence of type 2 diabetes mellitus (type 2 DM) in both sexes of a northern European population.

METHODS

A total of 14,223 randomly selected men and women were studied from 1976 to 1978. Patients with diabetes (self-reported type 2 DM or non-fasting plasma glucose >11.1 mmol/l) were excluded. Some 6154 women and 4733 men were studied and followed up in 1981-1983 or in 1991-1994. The significance of risk factors was examined by multiple logistic regression analysis.

RESULTS

Initially, a higher proportion of men than women had high, non-fasting blood glucose and triglycerides. Significantly more men (242, 5.4%) than women (152, 2.5%) developed type 2 DM. The odds ratio (OR) for developing diabetes with a BMI above 30 kg/m(2) compared to a BMI of 20-25 kg/m(2) was 8.1 in women and 6.3 in men; for a non-fasting plasma glucose of 8.4-11.0 mmol/l compared to a plasma glucose of 5.5-6.4, the ORs were 7.8 in women and 4.7 in men. The OR for developing diabetes in persons with a non-fasting triglyceride level above 2.0 mmol/l compared to 1.0-2.0 mmol/l was 1.8 in both sexes; women with non -fasting triglycerides below 1.0 mmol/l had an OR of 0.4.

CONCLUSION

In a randomly selected northern European population, significantly more men than women develop type 2 DM.

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.

The metabolic syndrome and the impact of diabetes on coronary heart disease mortality in women and men: the San Antonio Heart Study

PURPOSE

An explanation for the differential impact of diabetes on coronary heart disease (CHD) mortality in men and women is that diabetes and cardiovascular disease (CVD) share a common antecedent that differentially affects men and women. In the San Antonio Heart Study we examined the relationship between gender, the metabolic syndrome defined by the National Cholesterol Education Program (NCEP-MetS) and diabetes and their ability to predict CHD mortality.

METHODS

Over 15.5 years, 4996 men and women 25 to 64 years of age experienced 254 cardiovascular deaths, including 121 from CHD (International Classification of Diseases, Ninth Revision codes 410-414).

RESULTS

At baseline, NCEP-MetS occurred more often in men than in women among those with normal glucose levels (12.3% vs. 9.7%, p < 0.05), but less often in men than in women among those with diabetes (65.7% vs. 74.4%, p < 0.05). Adjusted for age, ethnic group, and a history of CVD, relative to women with neither diabetes nor NCEP-MetS, women with both had a 14-fold (hazard ratio [HR] = 14.3 [95% confidence interval: 6.62, 30.7]) increased risk of CHD mortality, whereas men had only a 4-fold (HR = 4.21 (95% confidence interval: 2.32, 7.65]) increased risk, respectively.

CONCLUSION

When diabetes occurred with NCEP-MetS, gender was a strong modifier of the joint effect of diabetes and NCEP-MetS on CHD mortality.

Abdominal obesity in BTBR male mice is associated with peripheral but not hepatic insulin resistance

Insulin resistance is a common feature of obesity. BTBR mice have more fat mass than most other inbred mouse strains. On a chow diet, BTBR mice have elevated insulin levels relative to the C57BL/6J (B6) strain. Male F1 progeny of a B6 x BTBR cross are insulin resistant. Previously, we reported insulin resistance in isolated muscle and in isolated adipocytes in this strain. Whereas the muscle insulin resistance was observed only in male F1 mice, adipocyte insulin resistance was also present in male BTBR mice. We examined in vivo mechanisms of insulin resistance with the hyperinsulinemic euglycemic clamp technique. At 10 wk of age, BTBR and F1 mice had a >30% reduction in whole body glucose disposal primarily due to insulin resistance in heart, soleus muscle, and adipose tissue. The increased adipose tissue mass and decreased muscle mass in BTBR and F1 mice were negatively and positively correlated with whole body glucose disposal, respectively. Genes involved in focal adhesion, actin cytoskeleton, and inflammation were more highly expressed in BTBR and F1 than in B6 adipose tissue. The BTBR and F1 mice have higher levels of testosterone, which may be related to the pathological changes in adipose tissue that lead to systemic insulin resistance. Despite profound peripheral insulin resistance, BTBR and F1 mice retained hepatic insulin sensitivity. These studies reveal a genetic difference in body composition that correlates with large differences in peripheral insulin sensitivity.

Alcohol for the prevention of type 2 diabetes mellitus?

While diabetes mellitus is recognized clinically as a complication of alcohol dependence, in the last 15 years several large prospective studies have demonstrated a significant reduction in risk of incident type 2 diabetes in moderate drinkers. In this article, we review prospective studies on the association between alcohol consumption and incidence of diabetes. Few prospective studies have demonstrated an unequivocal positive association between alcohol use and incidence of diabetes. A number of large prospective studies have now demonstrated an inverse association: typically a 40% risk reduction after controlling for other major risk factors. Studies based on cohorts of health professionals have not demonstrated an increased risk of diabetes with heavier consumption, but these cohorts contain few heavy drinkers. Some cohorts drawn from the general population have shown a J- or U-shaped association between level of alcohol consumption and incidence of diabetes. Frequent moderate drinking has been reported to be associated with lower risk than infrequent drinking. There have been contradictory reports on the importance of the type of alcoholic beverage and whether the effect of alcohol differs according to the bodyweight of the drinker. We conclude that like many other chronic diseases, there is a delicate balance between the harmful and beneficial effects of alcohol on the incidence of diabetes. In moderate amounts, drinking is associated with a reduced risk of diabetes, whereas in higher amounts with an increased risk.

Intensive lifestyle intervention or metformin on inflammation and coagulation in participants with impaired glucose tolerance

Increases in subclinical inflammation (C-reactive protein [CRP]) and impaired coagulation have been associated with increased obesity and insulin resistance. Only a few small studies have examined the effect of lifestyle changes, such as weight loss, increased physical activity, and insulin-sensitizing intervention on inflammation and coagulation. The Diabetes Prevention Program (DPP) clinical trial studied the effect of an intensive lifestyle intervention or metformin on progression to diabetes relative to placebo in 3,234 adults with impaired glucose tolerance. The effects of these interventions on CRP and fibrinogen at 12 months are examined in this report. Metformin reduced CRP in women compared with the placebo group. In men, the median changes in CRP from baseline to 1 year were -33% in the lifestyle group, -7% in the metformin group, and +5% in the placebo group. In women, the changes in CRP from baseline to follow-up were -29% in the lifestyle group, -14% in the metformin group, and 0% in the placebo group. In the lifestyle group weight loss rather than increased physical activity seems to account for most of the changes in CRP. Only modest reductions (although significant) were seen in fibrinogen levels in the lifestyle group relative to the metformin and placebo group. Lifestyle intervention reduced levels of nontraditional cardiovascular risk factors relative to both placebo and to a lesser degree to metformin.

Type 2 diabetes and impaired fasting glucose in American Indians aged 5-40 years: the Cherokee diabetes study

PURPOSE

To estimate the prevalence of type 2 diabetes and impaired fasting glucose (IFG) and to study several potential risk factors for type 2 diabetes among Oklahoma Cherokees aged 5 to 40 years.

METHODS

A random sample of 2205 members of the Cherokee Nation of Oklahoma aged 5 to 40 years was recruited. Demographic, clinical, and laboratory data were collected. Type 2 diabetes and IFG were determined using the 1997 American Diabetes Association (ADA) criteria. Relationships between type 2 diabetes and potential risk factors were examined by univariate and multivariate regression methods.

RESULTS

According to ADA criteria, the age-adjusted prevalence proportions of type 2 diabetes were 4.3% in females and 4.8% in males. Among the 89 individuals who had type 2 diabetes, 31 were newly diagnosed. Thirty-two (1.5%, 18 females and 14 males) were found to have IFG. The prevalence of type 2 diabetes and IFG increased with age, number of parents with diabetes, obesity, degree of Indian heritage, high triglyceride value, and low HDL cholesterol.

CONCLUSIONS

The increasing prevalence of type 2 diabetes in young American Indians is alarming. The findings must be disseminated to the Indian communities and their health care providers. Preventive measures and early detection programs must be designed and implemented for children and adolescents in this population.

Comparison of electrocardiogram findings and lifestyles between urbanized people and ger-living people in Ulaanbaatar, Mongolia

In Ulaanbaatar, lifestyles differ between urbanized people (group A) and ger (tent)-living people (group B). Group A earn high annual incomes and live in houses or apartments. Group B (who had moved to Ulaanbaatar from nomadic areas) earn low incomes and live in narrow gers. In 2002, we investigated daily food intake, health status, and electrocardiogram (ECG) in these groups. In total, 256 subjects (group A, 142; group B, 114) were enrolled. Group A ate meat, vegetables, and fruits high enough by a Western style. Group B consumed meat but ate only small amounts of vegetables and fruits. They took a lot of fat, however, the serum lipid levels of them were not so high. The fat source as energy was plant oil for cooking rather than meat. Several abnormal ECG findings including left ventricular hypertrophy (LVH) were found in 32 (22.5%) of group A and 50 (43.9%) of group B (P < 0.001). LVH was also found more in group B than in group A. LVH in group A males was accompanied by high body weight (BW), hypertension, and high LDL-cholesterol, whereas LVH in group B males seemed to be related to an unbalanced diet, high salt intake, smoking, and some low socio-economic problems. In order to promote health condition, such risk factors should securely be eliminated from the lifestyles.

Prevalence of diego blood group Dia antigen in mongolians: comparison with that in Japanese

The Diego blood group is composed of Di(a) and Di(b) antigens. Prevalence of the Di(a) antigen is known to be different among races. The Di(a) antigen is generally found in Oriental people. Thus, it is called a Mongoloid factor. In Japanese, the prevalence of this antigen is 8.78%. However, the prevalence in Mongolians had not previously been examined. In September of 2002, we determined this antigen among inhabitants of Ulaanbaatar. It was found in 24 of 242 subjects (9.92%). This prevalence approximates that in Japanese. The Rh blood group phenotypes also showed patterns similar to those in Japanese. These results are not contrary to the presumption that Mongolians and Japanese may have a common racial background.

Elevated carotid artery intima-media thickness levels in individuals who subsequently develop type 2 diabetes

OBJECTIVE

We examined whether B-mode ultrasound-detected carotid artery intima-media thickness (IMT) was elevated before the onset of clinical diabetes.

METHODS AND RESULTS

The study population for these analyses included 1127 nondiabetic participants, 66 prediabetic participants, and 303 diabetic participants with a mean age of 49.8 years who participated in the Mexico City Diabetes Study, a prospective cohort study. Common carotid artery (CCA) and internal carotid artery (ICA) IMTs were measured bilaterally by B-mode ultrasound. Age- and sex-adjusted mean ICA and CCA IMTs were both significantly higher among prediabetic individuals [0.81 mm [95% confidence interval (CI), 0.75-0.88] and 0.72 mm [95% CI, 0.69-0.75], respectively] than in individuals who remained free of diabetes [0.71 mm (95% CI, 0.69-0.72) and 0.69 mm (95% CI, 0.68-0.69), respectively]. However, after adjustment for established cardiovascular risk factors, ICA IMT, but not CCA IMT, remained significantly higher among prediabetic individuals [0.81 mm (95% CI, 0.75-0.88) and 0.71 mm (95% CI, 0.68-0.74)] than in individuals who remained free of diabetes [0.71 mm (95% CI, 0.69-0.72) and 0.69 mm (95% CI, 0.68-0.70)].

CONCLUSIONS

The present study provides direct evidence at the vascular level that atherosclerosis levels are elevated before the clinical onset of diabetes.

Inflammation in the prediabetic state is related to increased insulin resistance rather than decreased insulin secretion

BACKGROUND

Elevated levels of proinflammatory proteins are predictive of both cardiovascular (CV) disease and type 2 diabetes. Previously, atherogenic changes in traditional CV risk factors in the prediabetic state were mainly seen in insulin-resistant subjects rather than in those with a predominant defect in insulin secretion.

METHODS AND RESULTS

We studied in prediabetic individuals from the Insulin Resistance Atherosclerosis Study (IRAS) the relation of C-reactive protein (CRP), plasminogen activator inhibitor (PAI)-1, and fibrinogen to defects in insulin sensitivity (SI) and first-phase insulin secretion, respectively, as assessed using a frequently sampled intravenous glucose tolerance test. One hundred forty-eight of 906 (16.3%) nondiabetic individuals developed diabetes after a mean follow-up of 5.2 years. Prediabetic individuals who were insulin resistant had higher levels of PAI-1 (mean [95% CI], 25.83 ng/mL [22.42 to 29.77] versus 16.31 ng/mL [12.56 to 21.18]; P=0.003) and CRP (mean [95% CI], 2.88 mg/L [2.33 to 3.56] versus 1.68 mg/L [1.13 to 2.49]; P=0.018) than insulin-sensitive individuals, but individuals with decreased acute insulin response tended to have lower rather than higher levels of inflammatory proteins compared with those with high insulin secretion. Prediabetic subjects who were predominantly insulin resistant had higher levels of inflammatory proteins compared with both prediabetic subjects with decreased insulin secretion as well as nonconverters. By contrast, prediabetic subjects with a predominant defect in first-phase insulin secretion had levels of inflammatory proteins indistinguishable from those in nonconverters.

CONCLUSIONS

We have shown an increased proinflammatory state in prediabetic individuals who are predominantly insulin resistant but not in those with a primary defect in beta-cell function. These results provide additional evidence that prediabetic subjects may be at an increased risk of heart disease, and this risk seems to be restricted to subjects with high insulin resistance.

Insulin resistance, inflammation, and the prediabetic state

Type 2 diabetes is associated with a marked increase in the incidence of coronary artery disease (CAD); however, the correlation between glycemia and CAD in patients with type 2 diabetes is only modestly positive. This relatively weak association between glycemia and CAD in subjects with diabetes may be caused by the existence of an atherogenic prediabetic state. In the San Antonio Heart Study, subjects who start with normal glucose tolerance and later develop type 2 diabetes have increased triglyceride levels, increased systolic blood pressure, and decreased levels of high-density lipoprotein cholesterol before the onset of type 2 diabetes. The basis for these atherogenic prediabetic changes may be related to insulin resistance rather than reduced insulin secretion. Recently, interest has focused on a possible role of fibrinolysis and increased subclinical inflammation, as determined by high-sensitivity C-reactive protein (CRP) levels. The Insulin Resistance Atherosclerosis Study found that insulin resistance, as determined by a frequently sampled glucose tolerance test, is significantly related to higher CRP levels, higher fibrinogen, and higher plasminogen activator inhibitor-1 (PAI-1) levels. The investigators also have shown that high PAI-1 and CRP levels are predictors of the development of type 2 diabetes. In addition, the Women's Health Study has shown that high CRP levels predict type 2 diabetes. Insulin-sensitizing interventions have been demonstrated to reduce these nontraditional risk factors. Rosiglitazone, an agent with insulin-sensitizing properties, decreases PAI-1 and CRP levels. Some of the adverse cardiovascular effects seen in patients with type 2 diabetes may be reversed by insulin-sensitizing agents.

Serum lipoproteins in the diabetes control and complications trial/epidemiology of diabetes intervention and complications cohort: associations with gender and glycemia

OBJECTIVE

To relate the nuclear magnetic resonance (NMR)-determined lipoprotein profile, conventional lipid and apolipoprotein measures, and in vitro oxidizibility of LDL with gender and glycemia in type 1 diabetes.

RESEARCH DESIGN AND METHODS

In the 1997-1999 Diabetes Control and Complications Trial/Epidemiology of Diabetes Intervention and Complications (DCCT/EDIC) cohort, serum from 428 women and 540 men were characterized by conventional lipids, NMR, apolipoprotein levels, and LDL susceptibility to in vitro oxidation. Simple and partial correlation coefficients were calculated for each lipoprotein-related parameter versus gender, with and without covariates (age, diabetes duration, concurrent HbA(1c), DCCT randomization, hypertension, BMI, waist-to-hip ratio, and albuminuria). For concurrent HbA(1c), data were analyzed as above, exchanging gender for HbA(1c). Associations were significant if P < 0.05.

RESULTS

Although men and women had similar total and LDL cholesterol and triglycerides, men exhibited the following significant percent differences in NMR profiles versus women: small VLDL 41; IDL -30; medium LDL 39; small LDL 21; large HDL -32; small HDL 35; LDL particle concentration 4; VLDL and HDL diameters -8 and -4, respectively. Small VLDL, small HDL, medium LDL (women only), small LDL (men only), and LDL particle concentration were positively correlated, and HDL size was inversely correlated, with concurrent HbA(1c). NMR profile was unrelated to prior DCCT randomization. Susceptibility of LDL to oxidation was unrelated to gender and glycemia.

CONCLUSIONS

Male gender and poor glycemia are associated with a potentially more atherogenic NMR lipoprotein profile. Neither gender nor glycemia influence LDL oxidation in vitro.

Evidence for distinct genetic effects on obesity and lipid-related CVD risk factors in diabetic compared to nondiabetic American Indians: the Strong Heart Family Study

BACKGROUND

The relationship between diabetes and increased cardiovascular disease (CVD) risk is well established. Previous data from the Strong Heart Family Study (SHFS) have demonstrated significant heritabilities for CVD risk factors and implicated diabetes as an important predictor of several of the phenotypes in three large groups of American Indians in Arizona (AZ), Oklahoma (OK), and the Dakotas (DK). However, the genetic architecture of this relationship is not well understood. The purpose of the present paper is to determine whether the genetic effects on CVD risk factors in the SHFS are different in diabetic and nondiabetic individuals.

METHODS

Approximately 950 men and women, 18 years or older, in 32 extended families, were examined between 1997 and 1999. Interaction between genotype and diabetes status was estimated for nine CVD risk factors [body fat mass (FAT), body mass index (BMI), high-density lipoprotein cholesterol (HDL-C), log-transformed fibrinogen, log-transformed triglycerides, log-transformed urinary albumin : creatinine ratio (LACR), plasminogen activator inhibitor 1 (PAI-1), systolic blood pressure (SBP), and waist-to-hip ratio (WHR)], using a maximum likelihood variance decomposition technique.

RESULTS

We found evidence that genetic factors influencing BMI, FAT, log-transformed triglycerides, HDL-C, and WHR are differentially expressed in individuals with diabetes compared to those without diabetes.

CONCLUSION

Thus, in the environmental and genetic milieu of diabetes, there may be distinct genetic determinants of various CVD risk factors.

Deterioration of the metabolic risk profile in women. Respective contributions of impaired glucose tolerance and visceral fat accumulation

OBJECTIVE

To determine whether the impaired glucose tolerance (IGT) state contributes to the deterioration of the metabolic profile in women after taking into account the contribution of visceral adipose tissue (AT) accumulation, as measured by computed tomography.

RESEARCH DESIGN AND METHODS

We studied 203 women with normal glucose tolerance (NGT) and 46 women with IGT, defined as a glycemia between 7.8 and 11.1 mmol/l measured 2 h after a 75-g oral glucose load.

RESULTS

Women with IGT were characterized by a higher visceral AT accumulation and by higher concentrations of fasting plasma glucose, insulin, and C-peptide as well as by higher plasma concentrations of cholesterol, triglycerides, and apolipoprotein B (apoB) and by greater cholesterol-to-HDL-cholesterol ratio, reduced LDL peak particle size, lower HDL-cholesterol and HDL2-cholesterol concentrations, and higher blood pressure (P < 0.01) than women with NGT. When we matched 27 pairs of women for visceral AT and fat mass as well as for menopausal status, differences previously found in LDL-cholesterol, LDL peak particle size, HDL-cholesterol, and HDL2-cholesterol concentrations as well as in the cholesterol-to-HDL-cholesterol ratio and blood pressure were eliminated, whereas triglyceride concentrations remained significantly higher in women with IGT.

CONCLUSIONS

A high visceral AT accumulation is a major factor involved in the deterioration of many metabolic variables in women with IGT, with the notable exception of triglyceride concentrations, which remained significantly different between women with NGT and women with IGT after adjustment for visceral fat.

Insulin-resistant prediabetic subjects have more atherogenic risk factors than insulin-sensitive prediabetic subjects: implications for preventing coronary heart disease during the prediabetic state

BACKGROUND

Subjects who convert to type 2 diabetes mellitus have increased cardiovascular risk factors relative to nonconverters. However, it is not known whether these atherogenic changes in the prediabetic state are predominantly due to insulin resistance, decreased insulin secretion, or both.

METHODS AND RESULTS

We examined this issue in the 7-year follow-up of the San Antonio Heart Study, in which 195 of 1734 subjects converted to type 2 diabetes. At baseline, converters had significantly higher body mass index, waist circumference, triglyceride concentration, and blood pressure and lower HDL cholesterol than nonconverters. Atherogenic changes in converters were markedly attenuated (and no longer significant) after adjustment for the homeostasis model assessment of insulin resistance (HOMA IR, a surrogate for insulin resistance); in contrast, the differences in risk factors between converters and nonconverters increased after adjustment for the ratio of early insulin increment to early glucose increment (DeltaI(30-0)/DeltaG(30-0)) during an oral glucose tolerance test (a surrogate for insulin secretion). We also compared converters who had a predominant insulin resistance (high HOMA IR and high DeltaI(30-0)/DeltaG(30-0)) (n=56) and converters who had a predominant decrease in insulin secretion (low HOMA IR and low DeltaI(30-0)/DeltaG(30-0)) (n=31) with nonconverters (n=1539). Only the converters who were insulin resistant had higher blood pressure and triglyceride levels and lower HDL cholesterol levels than nonconverters.

CONCLUSIONS

Our data suggest that atherogenic changes in the prediabetic state are mainly seen in insulin-resistant subjects and that strategies to prevent type 2 diabetes might focus on insulin-sensitizing interventions rather than interventions that increase insulin secretion because of potential effects on cardiovascular risk.