High-density lipoprotein-cholesterol and incident type 2 diabetes mellitus among African Americans: The Jackson Heart Study.

AIMS: Accruing evidence suggests an association between high-density lipoprotein cholesterol (HDL-C) and incident diabetes. However, there is a paucity of data on the link between HDL-C and diabetes, especially among African Americans (AAs). We aimed to assess the association of HDL-C and its fractions with incident type 2 diabetes among AAs. METHODS: We included Jackson Heart Study participants who attended visit 1 (2001-2004), were free from diabetes and were not treated with lipid-modifying medications. Incident diabetes was assessed at two subsequent-yearly visits (2 and 3). We cross-sectionally assessed the association of HDL-C and insulin resistance (IR) using multivariable linear models. We prospectively assessed the association of HDL-C and its fractions with incident diabetes using multivariable Cox regression models. RESULTS: Among 2829 participants (mean age: 51.9 ± 12.4 years, 63.9% female), 487 participants (17%) developed new-onset diabetes, over a median follow-up of 8 years. In adjusted models, a higher HDL-C concentration was associated with a lower odds of IR (odds ratio [OR] per standard deviation [SD] increment: OR 0.56 [95% confidence interval, CI 0.50-0.63], p < 0.001). In adjusted models, a higher HDL-C concentration was associated with a lower risk of diabetes (HR per SD increment: 0.78 [95% CI 0.71, 0.87], p < 0.001; HR for highest vs. the lowest tertile of HDL-C was 0.56 [95% CI: 0.44, 0.71], p < 0.001). CONCLUSION: In a sample of African-American adults not on any lipid-modifying therapy, high HDL-C concentrations were inversely associated with the risk of new-onset diabetes. These findings suggest a strong link between HDL-C metabolism and glucose regulation.

Effect of Serum Ferritin on the Association Between Coffee Intake and Hyperuricemia Among American Women: The National Health and Nutrition Examination Survey.

Background Accruing evidence suggests an inverse relationship between coffee intake and serum uric acid. The mechanism(s) explaining this inverse relationship remains elusive. The aim of this study was to assess if the association between coffee intake and hyperuricemia is mediated via serum ferritin in women. Methods We pooled data from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES). We included women with complete information on all key variables. Coffee intake was classified as none, <1 cup/day, 1-3 cups/day, and ≥4 cups/day. Hyperuricemia was defined as serum uric acid >5.7 mg/dL. We assessed the association between coffee intake and hyperuricemia using logistic regression. Path analysis was used to examine whether serum ferritin mediated the effect of coffee on hyperuricemia. Results Among 2,139 women (mean age: 31.2 years [SD: 9.2]), mean serum uric acid was 4.4 mg/dL (SD: 1.0), and 227 (10.6%) had hyperuricemia. In multivariate logistic regression models, intake of ≥4 cups/day of coffee was associated with lower odds of hyperuricemia (OR 0.28 [95% CI: 0.09, 091], P=0.035). The total direct and indirect effect of coffee on hyperuricemia via serum ferritin was -0.16, P=0.009 and -8.1 × 10- 3, P=0.204, respectively. Conclusion Among women, moderate coffee consumption was inversely related to hyperuricemia by direct effect, rather than indirectly through the effects of serum ferritin. These findings suggest that serum ferritin does not mediate the inverse association between coffee and hyperuricemia in women.

Effect of Topical Capsaicin on Painful Sensory Peripheral Neuropathy in Patients with Type 2 Diabetes: A Double-Blind Placebo-Controlled Randomised Clinical Trial.

Objective The aim of this study was to evaluate the efficacy of capsaicin in inducing significant pain relief in a population of sub-Saharan African type 2 diabetic patients with painful peripheral neuropathy. Design This was a prospective double-blind placebo-controlled randomised clinical trial. Setting A single tertiary-level hospital diabetes center in Yaounde, Cameroon. Participants Twenty-two participants with type 2 diabetes mellitus, presenting with painful diabetic neuropathy, aged 18 years and above. Intervention Participants were equally randomised to capsaicin or placebo. Each drug was to be applied on the lower limbs thrice daily. Follow-up was done every two weeks for eight weeks.  Main outcome measure Reduction in the median pain score from baseline, as assessed by the Visual Analogue Scale.  Results Twenty-two participants aged 57.5 (50-60) years with a median pain intensity of 6.8 units in the capsaicin group and 5.8 units in the placebo group were included; at inclusion, there was no significant difference in the two groups (p=0.29). After two weeks, the value of pain intensity was 3.3 [2.5-4.0] vs 5.0 [4.0-7.4] (p=0.003); at week four, 3.0 [2.5-3.3] vs 5.0 [4.2-5.5] (p=0,02); at week six, 3.3 [2.5-4.0] vs 4.8 [4.0-6.0] (p=0.03); and at week eight, 6.6 [6.0-7.0] vs 5.2 [5.0-6.0] (p=0.54) for capsaicin and placebo respectively. Conclusion This study, carried out due to a paucity of information on the effect of capsaicin and painful diabetic neuropathy in sub-Saharan African diabetes patients, shows that capsaicin significantly reduces neuropathic pain with worsening after eight weeks of use. Trial registration number Pan Africa Trial Registry: PACTR202003714748946.