Dyslipidaemia in African Americans, Hispanics and whites with type 2 diabetes mellitus and hypertension

Impaired functional exercise capacity and greater cardiovascular response to the 6-min walk test in congenital generalized lipodystrophy

BACKGROUND

Congenital Generalized Lipodystrophy (CGL) is an ultra-rare disease characterized by metabolic disorders. However, the evaluation of functional exercise capacity, cardiovascular (CV) response to exercise, and peripheral arterial disease (PAD) in CGL is scarce. Here we evaluated the performance and CV response to exercise and their association with PAD in CGL compared to healthy individuals.

METHODS

Twelve CGL and 12 healthy subjects matched for age and gender were included. Functional exercise capacity, CV response, and PAD were measured using the six-minute walk test (6MWT) and ankle-brachial index (ABI), respectively.

RESULTS

At baseline, CGL subjects showed reduced predicted walked distance (6MWD) (p = 0.009) and increased heart rate (HR), systolic (SBP), and diastolic (DBP) pressures compared to healthy subjects (p < 0.05). Most CGL subjects presented normal ABI values (1.0 ≤ ABI ≤ 1.4). Only 25% (n = 3) had ABI ≤ 0.9. CGL subjects did not present changes in ABI and blood pressure 12 months after metreleptin (MLP) replacement, but they walked a greater 6MWD than baseline (p = 0.04). Further, 6MWD and right ABI measurements were positively correlated in CGL subjects (p = 0.03). Right ABI negatively correlated with glucose, triglycerides, and VLDL-c (p < 0.05).

CONCLUSIONS

We observed that CGL subjects had lower functional exercise capacity and higher cardiovascular effort for similar performance of 6MWT, suggesting that strategies for decreasing exercise effort in this population should be essential. Furthermore, better physical performance was associated with high ABI in CGL. Additional studies are needed to clarify leptin's role in preserving functional exercise capacity in CGL.

Identification of hypertriglyceridemia based on bone density, body fat mass, and anthropometry in a Korean population

BACKGROUND

Hypertriglyceridemia is strongly associated with the risks of cardiovascular disease, coronary heart disease, and metabolic syndrome. The relationship between hypertriglyceridemia or high triglyceride levels and bone mineral density remains controversial. Furthermore, to date, no study has simultaneously examined the association among hypertriglyceridemia, bone area, bone mineral content, bone mineral density, body fat mass, and anthropometrics. The present study aimed to evaluate the association among hypertriglyceridemia, anthropometrics and various bone density and body fat composition variables to identify the best indicator of hypertriglyceridemia in a Korean population.

METHODS

The data were obtained from the fifth Korea National Health and Nutrition Examination Survey. In total, 3918 subjects aged 20-80 years participated in this study. In the variable analysis of the waist circumference (WC), trunk fat mass (Trk-Ft), body mass index, etc., a binary logistic regression analysis was performed to examine the significance of the differences between the normal group and hypertriglyceridemia groups.

RESULTS

In both men and women, the WC showed the strongest association with hypertriglyceridemia in the crude analysis (odds ratio (OR) = 1.738 [confidence interval = 1.529-1.976] and OR = 2.075 [1.797-2.397]), but the Trk-Ft was the most strongly associated with the disease after adjusting for age and body mass index (adjusted OR = 1.565 [1.262-1.941] and adjusted OR = 1.730 [1.291-2.319]). In particular, the Pelvis area (Plv-A) was the most significant among the bone variables in women (adjusted OR = 0.641 [0.515-0.796]). In the predictive power analysis, the best indicator of hypertriglyceridemia was WC in women (the area under the receiver operating characteristic curve (AUC) = 0.718 [0.685-0.751]) and Trk-Ft in men (AUC = 0.672 [0.643-0.702]). The WC was also the most predictive among the anthropometric variables in men (AUC = 0.670 [0.641-0.700]). The strength of the association and predictive power was stronger in women than in men.

CONCLUSIONS

The WC in women and Trk-Ft in men exhibited the best predictive power for hypertriglyceridemia. Our findings support the use of basic information for the identification of hypertriglyceridemia or high triglyceride levels in initial health screening efforts.

Ankle-brachial index and incident diabetes mellitus: the atherosclerosis risk in communities (ARIC) study

Background

Individuals with peripheral artery disease (PAD) often have reduced physical activity, which may increase the future risk of diabetes mellitus. Although diabetes is a risk factor for PAD, whether low ankle-brachial index (ABI) predates diabetes has not been studied.

Methods

We examined the association of ABI with incident diabetes using Cox proportional hazards models in the ARIC Study. ABI was measured in 12,247 black and white participants without prevalent diabetes at baseline (1987–1989). Incident diabetes cases were identified by blood glucose levels at three subsequent visits (1990–92, 1993–95, and 1996–98) or self-reported physician diagnosis or medication use at those visits or during annual phone interview afterward through 2011.

Results

A total of 3305 participants developed diabetes during a median of 21 years of follow-up. Participants with low (≤0.90) and borderline low (0.91–1.00) ABI had 30–40% higher risk of future diabetes as compared to those with ABI of 1.10–1.20 in the demographically adjusted model. The associations were attenuated after further adjustment for other potential confounders but remained significant for ABI 0.91–1.00 (HR = 1.17, 95% CI 1.04–1.31) and marginally significant for ABI ≤ 0.90 (HR = 1.19, 0.99–1.43). Although the association was largely consistent across subgroups, a stronger association was seen in participants without hypertension, those with normal fasting glucose, and those with a history of stroke compared to their counterparts.

Conclusions

Low ABI was modestly but independently associated with increased risk of incident diabetes in the general population. Clinical attention should be paid to the glucose trajectory among people with low ABI but without diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0476-4) contains supplementary material, which is available to authorized users.

Association of clinical and therapeutic factors with incident dyslipidemia in a cohort of human immunodeficiency virus-infected and non-infected adults: 1994-2011

OBJECTIVE

The aim of this study was to determine the incidence rate of dyslipidemia in a retrospective cohort of human immunodeficiency virus (HIV)-infected and non-HIV-infected adults and to evaluate the association of incident dyslipidemia with exposure to combination antiretroviral therapy (cART).

METHODS

The study cohort included HIV-infected individuals and a matched group of non-HIV-infected individuals served through the South Carolina Medicaid database in 1994-2011. Linkage with the HIV/AIDS surveillance database provided time-varying viro-immunological status. Time-dependent proportional hazards analysis and marginal structural models were used to assess the demographic, therapeutic, and clinical factors associated with incident dyslipidemia.

RESULTS

Among 13,632 adults with a median age of 39 years, the overall incidence rate per 1000 person years of dyslipidemia was higher in cART-treated compared to cART-naïve and matched non-HIV groups (24.55 vs. 14.32 vs. 23.23, respectively). Multivariable results suggested a significantly higher risk of dyslipidemia in the cART-treated HIV-infected group [adjusted hazard ratio (aHR)=1.18; 95% confidence interval (CI)=1.07-1.30] and a significantly lower risk in the cART naïve HIV-infected group (aHR=0.66; CI=0.53-0.82) compared to the control non-HIV-infected group. Marginal structural modeling suggested a significant association between incident dyslipidemia and exposure to both protease inhibitor- [adjusted rate ratio (aRR)=1.27; CI=1.08-1.49] and non-nucleoside reverse transcriptase inhibitor- (aRR=1.78; CI=1.19-2.66) based cART regimens. Pre-existing hypertension, obesity, and diabetes increased the risk of dyslipidemia, whereas hepatitis C virus, lower CD4(+) T cell count, and higher HIV viral load had a protective effect.

CONCLUSIONS

Incident dyslipidemia is lower in the early stages of HIV infection, but may significantly increase with cumulative exposure to cART. Viro-immunological status and underlying comorbidities have a strong association with the onset of dyslipidemia.

Carbohydrate nutrition differs by diabetes status and is associated with dyslipidemia in Boston Puerto Rican adults without diabetes

Puerto Rican adults have a greater prevalence of type 2 diabetes (T2D) and lower HDL-cholesterol (HDL-C) than the general U.S. population. Carbohydrate nutrition may play a role in this disparity. Cross-sectional analyses included data from 1219 Puerto Ricans aged 45-75 y enrolled in the Boston Puerto Rican Health Study. Using the Pearson chi-square test and ANCOVA, lifestyle characteristics and dietary intake, as assessed by semiquantitative FFQ, were compared by T2D status based on fasting plasma glucose concentration and medication use. Food source rankings for carbohydrate, dietary glycemic load (GL), and fiber were obtained using the SAS procedure PROC RANK. Geometric mean plasma HDL-C and TG concentrations were compared across quintiles of dietary carbohydrate, glycemic index (GI), GL, and fiber by using ANCOVA and tests for linear trend. In multivariable analyses, individuals with T2D (39.5%) had lower dietary carbohydrate, GL, and total sugar intake from lower intake of sugar, fruit drinks, and soda compared with those without T2D. In individuals without T2D, dietary carbohydrate and GL were inversely associated with HDL-C (P < 0.0001). Associations between dietary fiber and HDL-C were confounded by carbohydrate intake, apparently from concurrent consumption of legumes with white rice, a refined carbohydrate food. No associations were observed between carbohydrate, dietary GI, GL, or fiber and TG. In conclusion, individuals with T2D showed evidence of dietary modification. Among those without diabetes, a high intake of refined carbohydrates was associated with decreased HDL-C. Longitudinal research on carbohydrate nutrition in relation to diabetes risk factors and blood lipids in Puerto Ricans is warranted.

Fatty acid and very low density lipoprotein metabolism in obese African American and Caucasian women with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is associated with increased plasma triglyceride (TG) concentrations, but African Americans (AA) have lower plasma TG than Caucasians (CC). We evaluated the hypothesis that obese AA women have lower plasma TG than obese CC women do because of differences in lipid kinetics. Eleven AA and 11 CC obese women with T2DM, matched on body mass index (BMI) (AA = 37 ± 1, CC = 37 ± 1 kg/m(2)), age, duration of diabetes, percentage body fat, and insulin sensitivity (S(I), determined by an intravenous glucose tolerance test), were studied. Plasma TG concentration (AA = 1.14 ± 0.11, CC = 1.88 ± 0.18 mmol/l), FFA rate of appearance (R(a)) into plasma (AA = 419 ± 27, CC = 503 ± 31 µmol·min(-1)), and total VLDL-TG secretion rate (AA = 18 ± 2, CC = 29 ± 4 µmol·min(-1)) were lower in AA than CC women (all P < 0.05). In contrast, plasma total apolipoprotein (apo)B-100 concentration (AA = 1,542 ± 179, CC = 1,620 ± 118 nmol/l) and VLDL-apoB-100 secretion rate (AA = 1.3 ± 0.1, CC = 1.3 ± 0.1 nmol·min(-1)) were similar in both groups, so the molar ratio of VLDL-TG secretion rate to VLDL-apoB-100 secretion rate was lower in AA women than in CC women. VLDL-TG concentration was lower in AA women due to lower total VLDL-TG secretion rate. However, the VLDL-apoB-100 secretion rate was the same in both groups, demonstrating that AA women secrete smaller VLDL particles containing less TG than do CC women.

Diabetic nephropathy among Mexican Americans

The incidence of diabetic nephropathy (DN) is growing rapidly worldwide as a consequence of the rising prevalence of Type 2 diabetes mellitus (T2DM). Among U.S. ethnic groups, Mexican Americans have a disproportionately high incidence and prevalence of DN and associated end-stage renal disease (ESRD). In communities bordering Mexico, as many as 90% of Mexican American patients with ESRD also suffer from T2DM compared to only 50% of non-Hispanic Whites (NHW). Both socio-economic factors and genetic predisposition appear to have a strong influence on this association. In addition, certain pathogenetic and clinical features of T2DM and DN are different in Mexican Americans compared to NHW, raising questions as to whether the diagnostic and treatment strategies that are standard practice in the NHW patient population may not be applicable in Mexican Americans. This article reviews the epidemiology of DN in Mexican Americans, describes the pathophysiology and associated risk factors, and identifies gaps in our knowledge and understanding that needs to be addressed by future investigations.

Unmet needs in Hispanic/Latino patients with type 2 diabetes mellitus

In the United States, the prevalence of adults who are overweight or obese is higher in Hispanics/Latinos compared with non-Hispanic whites. In addition, data from the National Health and Nutrition Examination Survey (NHANES) indicate that the prevalence of type 2 diabetes mellitus is consistently greater in racial/ethnic minority groups, such as Hispanics/Latinos, compared with non-Hispanic whites. In fact, data from the Centers for Disease Control and Prevention (CDC) from 2007 to 2009 suggest that the prevalence of type 2 diabetes is almost twice as high in Hispanics/Latinos compared with non-Hispanic whites (11.8% vs. 7.1%, respectively). Although genetics plays a role in the increased prevalence of type 2 diabetes in Hispanics/Latinos, cultural and environmental factors also contribute. In addition to the increased prevalence of type 2 diabetes in Hispanics/Latinos, evidence suggests that the patients in this population are often undertreated and, therefore, less likely to achieve control of their glucose, blood pressure, and lipid levels. Because individuals with type 2 diabetes have a 2- to 4-fold increased risk of cardiovascular disease compared with individuals with normal glucose levels, there is consensus that targeting environmental factors, particularly the development of obesity at an early age, is the most cost-effective approach to prevent the development of type 2 diabetes and its broad spectrum of complications, including cardiovascular disease. Cultural and socioeconomic barriers, such as language, cost, and access to goods and services, must be overcome to improve management of type 2 diabetes in this high-risk population. By increasing healthcare provider awareness and the availability of programs tailored to Hispanic/Latino individuals, the current treatment gap among ethnic minorities in the United States will progressively narrow, and eventually, disappear.

Periodontal disease in Hispanic Americans with type 2 diabetes

BACKGROUND

Diabetes is a major risk factor for the development of periodontal disease in certain populations. The prevalence of type 2 diabetes is increased in Hispanic Americans, but its impact on the extent and severity of periodontal disease in this population has not been determined.

METHODS

Sixty-three Hispanic Americans, aged 33 to 72 years, from South Texas were grouped based on the presence or absence of type 2 diabetes. Past medical histories, including smoking, were obtained. Periodontal status was evaluated by measuring probing depth (PD), clinical attachment level (CAL), plaque, bleeding on probing, visual gingival inflammation, and calculus.

RESULTS

Type 2 diabetes was associated frequently with major medical complications in this population. Diabetes was associated with significantly more calculus formation and tooth loss and an increased extent and severity of periodontitis. Subjects with diabetes had nearly three times the mean CAL and frequency of PD >6 mm than subjects without diabetes and nearly twice the frequency of moderate to advanced attachment loss (> or =3 mm). Smoking and diabetes had significant independent effects on mean CAL and the frequency of deep pockets. Diabetes and smoking combined were associated with a significantly higher frequency of sites with CAL > or =3 mm compared to healthy non-smokers, healthy smokers, and non-smokers with diabetes.

CONCLUSIONS

Hispanic Americans with type 2 diabetes had more supra- and subgingival calculus, an increased extent and severity of periodontal destruction, and an increased frequency of tooth loss due to periodontitis. An additive/synergistic contribution of type 2 diabetes and smoking for increasing the extent of periodontal disease was observed.

Disparities in A1C levels between Hispanic and non-Hispanic white adults with diabetes: a meta-analysis

OBJECTIVE

Hispanics have higher rates of diabetes and diabetes-related complications than do non-Hispanic whites. A meta-analysis was conducted to estimate the difference between the mean values of A1C for these two groups.

RESEARCH DESIGN AND METHODS

We executed a PubMed search of articles published from 1993 through July 2007. Data sources included PubMed, Web of Science, Cumulative Index to Nursing and Allied Health, the Cochrane Library, Combined Health Information Database, and Education Resources Information Center. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for Hispanics and non-Hispanic whites with diabetes were included. Studies were excluded if they included individuals <18 years of age or patients with pre-diabetes or gestational diabetes.

RESULTS

A total of 495 studies were reviewed, of which 73 contained data on A1C for Hispanics and non-Hispanic whites, and 11 met the inclusion criteria. Meta-analysis revealed a statistically significant mean difference (P < 0.0001) of -0.46 (95% CI -0.63 to -0.33), correlating to an approximately 0.5% higher A1C for Hispanics. Grouping studies by design (cross-sectional or cohort), method of data collection for A1C (chart review or blood sampling), and care type (managed or nonmanaged) yielded similar results.

CONCLUSIONS

In this meta-analysis, A1C was approximately 0.5% higher in Hispanic patients with diabetes than in non-Hispanic patients. Understanding the reasons for this disparity should be a focus for future research.

Protective effect of apolipoprotein E2 on coronary artery disease in African Americans is mediated through lipoprotein cholesterol

We studied the relationship of apolipoprotein E (apoE) isoforms and coronary artery disease (CAD) in 224 African Americans and 326 Caucasians undergoing diagnostic coronary angiography. The presence of CAD was defined as >50% stenosis in at least one artery. ApoE allele frequencies were 0.12, 0.62, and 0.26 for epsilon 2, epsilon 3, and epsilon 4, respectively, in African Americans and 0.08, 0.78, and 0.14 for epsilon 2, epsilon 3, and epsilon 4, respectively, in Caucasians. Among African Americans, CAD was present in 9 of 34 epsilon 2 carriers (26%), significantly smaller (P < 0.05) in proportion compared with 39 of 82 epsilon 3 carriers and 43 of 92 epsilon 4 carriers (48% and 47%, respectively), suggesting a protective effect of the epsilon 2 allele. No such difference was seen in Caucasians. In African Americans but not Caucasians, LDL cholesterol was lower in epsilon 2 carriers than in epsilon 3 and epsilon 4 carriers (106 vs. 127 and 134 mg/dl, respectively; P < 0.005). After adjusting for lipid levels, the association between apoE2 and CAD was no longer significant. Thus, the protective effect of apoE2 seen in African Americans could be explained by a favorable lipid profile in epsilon 2 carriers, whereas in Caucasians, the absence of such a protective effect could be attributable to the lack of effect of apoE2 on the lipid profile.

Disparities in HbA1c levels between African-American and non-Hispanic white adults with diabetes: a meta-analysis

OBJECTIVE

Among individuals with diabetes, a comparison of HbA(1c) (A1C) levels between African Americans and non-Hispanic whites was evaluated. Data sources included PubMed, Web of Science, the Cumulative Index to Nursing and Allied Health, the Cochrane Library, the Combined Health Information Database, and the Education Resources Information Center.

RESEARCH DESIGN AND METHODS

We executed a search for articles published between 1993 and 2005. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for African Americans and non-Hispanic whites with diabetes were included. Diabetic subjects aged <18 years and those with pre-diabetes or gestational diabetes were excluded. We conducted a meta-analysis to estimate the difference in the mean values of A1C for African Americans and non-Hispanic whites.

RESULTS

A total of 391 studies were reviewed, of which 78 contained A1C data. Eleven had data on A1C for African Americans and non-Hispanic whites and met selection criteria. A meta-analysis revealed the standard effect to be 0.31 (95% CI 0.39-0.25). This standard effect correlates to an A1C difference between groups of approximately 0.65%, indicating a higher A1C across studies for African Americans. Grouping studies by study type (cross-sectional or cohort), method of data collection for A1C (chart review or blood draw), and insurance status (managed care or nonmanaged care) showed similar results.

CONCLUSIONS

The higher A1C observed in this meta-analysis among African Americans compared with non-Hispanic whites may contribute to disparity in diabetes morbidity and mortality in this population.

Ethnic Disparities: Control of Glycemia, Blood Pressure, and LDL Cholesterol Among US Adults with Type 2 Diabetes

OBJECTIVE:

To examine ethnic disparities in the quality of diabetes care among adults with diabetes in the US through a systematic qualitative review.

DATA SOURCES:

Material published in the English language was searched from 1993 through June 2003 using PubMed, Web of Science, Cumulative Index to Nursing and Allied Health, the Cochrane Library, Combined Health Information Database, and Education Resources Information Center.

STUDY SELECTION AND DATA EXTRACTION:

Studies of patients with diabetes in which at least 50% of study participants were ethnic minorities and studies that made ethnic group comparisons were eligible. Research on individuals having prediabetes, those <18 years of age, or women with gestational diabetes were excluded. Reviewers used a reproducible search strategy. A standardized abstraction and grading of articles for publication source and content were used. Data on glycemia, blood pressure, and low-density lipoprotein cholesterol (LDL-C) were extracted in patients with diabetes. A total of 390 studies were reviewed, with 78 meeting inclusion criteria.

DATA SYNTHESIS:

Ethnic minorities had poorer outcomes of care than non-Hispanic whites. These disparities were most pronounced for glycemic control and least evident for LDL-C control. Most studies showed blood pressure to be poorly controlled among ethnic minorities.

CONCLUSIONS:

Control of risk factors for diabetes (glycemia, blood pressure, LDL-C) is challenging and requires routine assessment. These findings indicate that additional efforts are needed to promote diabetes quality of care among minority populations.

Serum fetuin-A in nondialyzed patients with diabetic nephropathy: relationship with coronary artery calcification

BACKGROUND

Fetuin-A is the most potent circulating inhibitor of calcium phosphorus precipitation and, possibly, an important mediator of insulin resistance.

METHODS

In order to determine the role of fetuin-A in the high coronary artery calcification (CAC) burden seen in nondialyzed individuals with diabetic nephropathy (DN), post-hoc analyses of data collected from a cross-sectional study of 88 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30 (Latinos); DN, N= 58 (Latinos and African Americans)].

RESULTS

The serum levels of fetuin-A were significantly higher among Latinos with DN when compared to either African Americans with DN or Latino diabetics with normoalbuminuria. Upon adjusting the data for race/ethnicity, there was a strong, direct relationship between serum fetuin-A levels and the CAC score (r= 0.22, P= 0.038) in the study cohort; however, a strong interaction between the nephropathy status and relationship of serum fetuin-A levels with CAC score was present (DN: r= 0.36, P= 0.006; diabetic controls, r= 0.0, P= 0.98). Among individuals with DN, the significance of the association persisted even after controlling the data for other predictors of CAC (partial r= 0.33, P= 0.018). Furthermore, there was a significant direct relationship between serum fetuin-A and serum triglycerides (partial r= 0.27, P= 0.01) and albumin (partial r= 0.30, P= 0.005), and an inverse relationship with glomerular filtration rate (r=-0.24, P= 0.03).

CONCLUSION

This first study in early stages of diabetic chronic kidney disease shows that the role of serum fetuin-A may be far more complex than previously described. During predialysis stage of DN, there is a direct relationship between serum fetuin-A levels and CAC score. The reasons for this association in the presence of nephropathy are unclear, but may be secondary to proatherogenic insulin resistance.