Ethnicity-specific obesity cut-points in the development of Type 2 diabetes - a prospective study including three ethnic groups in the United Kingdom

Aims: Conventional definitions of obesity, e.g. body mass index (BMI) ≥ 30 kg/m2 or waist circumference cut-points of 102 cm (men) and 88 cm (women), may underestimate metabolic risk in non-Europeans. We prospectively identified equivalent ethnicity-specific obesity cut-points for the estimation of diabetes risk in British South Asians, African-Caribbeans and Europeans. Methods: We studied a population-based cohort from London, UK (1356 Europeans, 842 South Asians, 335 African-Caribbeans) who were aged 40–69 years at baseline (1988–1991), when they underwent anthropometry, fasting and post-load (75 g oral glucose tolerance test) blood tests. Incident Type 2 diabetes was identified from primary care records, participant recall and/or follow-up biochemistry. Ethnicity-specific obesity cut-points in association with diabetes incidence were estimated using negative binomial regression. Results: Diabetes incidence rates (per 1000 person years) at a median follow-up of 19 years were 20.8 (95% CI: 18.4, 23.6) and 12.0 (8.3, 17.2) in South Asian men and women, 16.5 (12.7, 21.4) and 17.5 (13.0, 23.7) in African-Caribbean men and women, and 7.4 (6.3, 8.7), and 7.2 (5.3, 9.8) in European men and women. For incidence rates equivalent to those at a BMI of 30 kg/m2 in European men and women, age- and sex-adjusted cut-points were: South Asians, 25.2 (23.4, 26.6) kg/m2; and African-Caribbeans, 27.2 (25.2, 28.6) kg/m2. For South Asian and African-Caribbean men, respectively, waist circumference cut-points of 90.4 (85.0, 94.5) and 90.6 (85.0, 94.5) cm were equivalent to a value of 102 cm in European men. Waist circumference cut-points of 84.0 (74.0, 90.0) cm in South Asian women and 81.2 (71.4, 87.4) cm in African-Caribbean women were equivalent to a value of 88 cm in European women. Conclusions: In prospective analyses, British South Asians and African-Caribbeans had equivalent diabetes incidence rates at substantially lower obesity levels than the conventional European cut-points

Liver fat in adults with GH deficiency: comparison to matched controls and the effect of GH replacement

CONTEXT: Existing data regarding the association between growth hormone deficiency (GHD) and liver fat content are conflicting. OBJECTIVE: We aimed i) to assess intrahepatocellular lipid (IHCL) content in hypopituitary adults with GHD compared to matched controls and ii) to evaluate the effect of growth hormone (GH) replacement on IHCL content. DESIGN: Cross-sectional comparison and controlled intervention study. PATIENTS, PARTICIPANTS: Cross-sectional comparison: 22 hypopituitary adults with GHD and 44 healthy controls matched for age, BMI, gender and ethnicity. Intervention study: 9 GHD patients starting GH replacement (GH Rx group), 9 GHD patients not starting replacement therapy (non-GH Rx group). INTERVENTION: Intervention study:GH replacement for 6 months in the GH Rx group, dosage was titrated to achieve normal IGF-1 levels. MAIN OUTCOME MEASURES: IHCL content determined by proton magnetic resonance spectroscopy (1 H MRS). RESULTS: Cross-sectional comparison: There was no difference in IHCL content between GHD patients and healthy controls (1.89% (0.30, 4.03) vs. 1.14% (0.22, 2.32); p=0.2), the prevalence of patients with hepatic steatosis (IHCL of ≥ 5.56%) was similar in the two groups (22.7% vs. 15.9%; chi square probability = 0.4). Intervention study: The change in IHCL content over 6 months did not differ between the GH Rx group and the non-GH Rx group (-0.63 ± 4.53% vs. +0.11 ± 1.46%; p=0.6). CONCLUSIONS: In our study liver fat content and the prevalence of hepatic steatosis did not differ between hypopituitary adults with GHD and matched controls. In GHD patients GH replacement had no effect on liver fat content

Alcohol consumption alters insulin secretion and cardiac autonomic activity

BackgroundAlcohol may have a cardioprotective effect. One possible mechanism is by modifying insulin resistance/secretion. The aims of this study were: (i) to examine the effect of short-term alcohol consumption on the metabolic control of glucose tolerance; (ii) to study the influence of short-term alcohol consumption on cardiac autonomic activity using spectral analysis of heart rate variability.MethodsTwenty-one healthy subjects, in a randomized crossover design, either received three units of ethanol daily for 1 week or abstained from ethanol. The control of glucose tolerance was assessed using the intravenous glucose tolerance test with minimal modelling.ResultsThere was no difference in fasting glucose, fasting insulin or insulin sensitivity between the two groups. Alcohol showed a lower insulin first phase insulin response (no alcohol 659·0 ± 394·1 SD, alcohol 535·2 ± 309·1) pmol L?1 min?1, P = 0·027). There was no difference in heart rate or blood pressure but a significant difference in the ratio of high to low frequency spectral power of heart rate variability; (no alcohol 4·55 ± 3·78, alcohol 8·16 ± 6·77, P = 0·033). This suggests decreased sympathetic and/or increased vagal modulation of heart rate in the alcohol group.ConclusionThe finding of no difference in insulin sensitivity between the two groups contrasts with, but does not entirely contradict, the results of previous epidemiological studies – perhaps suggesting that longer term changes such as liver enzyme induction may be important. The difference in insulin secretion questions the validity of previous studies of the influence of alcohol on insulin sensitivity, where insulin levels were used as a surrogate for insulin resistance

The effect of hormone replacement therapy and tibolone on lipoprotein (a) concentrations in postmenopausal women: A systematic review and meta-analysis

Objective Data on the effect of hormone replacement therapy (HRT) and tibolone on lipoprotein (a) [Lp(a)], an independent risk factor for cardiovascular disease, are heterogeneous and conflicting. Studies of the effect of HRT and tibolone on Lp(a) concentrations in post-menopausal women are reviewed in this meta-analysis. Design and methods MEDLINE, Scopus, EMBASE and Cochrane databases were searched (up to February 10, 2017). Two researchers identified randomized controlled studies and extracted data. Potential controversies were resolved by a third reviewer. Results In 24 eligible studies, HRT caused a significant reduction in Lp(a) concentrations compared with placebo or no treatment [mean relative difference: −20.35%, 95% Confidence Interval (CI): −25.33% to −15.37%, p < 0.0001], with significant heterogeneity between studies (I2 = 98.5%), but without evidence of publication bias. No significant effect was found for tibolone (n = 7) (mean relative difference: −23.84%, 95% CI: −63.43% to 15.74%, p = 0.238) (I2 = 98.7%, but without publication bias). Oral estrogen caused a greater reduction in Lp(a) concentrations than transdermal estrogen (n = 10) (mean relative difference: 37.66%, 95% CI: 16.84% to 58.48%, p < 0.0001), with significant heterogeneity between studies (I2 = 99%), but no evidence of publication bias. No difference was observed when continuous was compared with cyclical HRT, conventional with low-dose estrogen, and estrogen monotherapy with estrogen combined with progestogen. No difference was observed between HRT and tibolone regarding their effect on Lp(a). Conclusions HRT significantly decreases Lp(a) concentrations, with oral being more effective than transdermal estradiol. The type of HRT, dose of estrogen and addition of progestogen do not seem to modify the Lp(a)-lowering effect of HRT. © 2017 Elsevier B.V

Uric acid in chronic heart failure: A marker of chronic inflammation

BACKGROUND: Chronic heart failure is associated with hyperuricaemia and elevations in circulating markers of inflammation. Activation of xanthine oxidase, through free radical release, causes leukocyte and endothelial cell activation. Associations could therefore be expected between serum uric acid level, as a marker of increased xanthine oxidase activity, and markers of inflammation. We have explored these associations in patients with chronic heart failure, taking into account the hyperuricaemic effects of diuretic therapy and insulin resistance. METHODS AND RESULTS: Circulating uric acid and markers of inflammation were measured in 39 male patients with chronic heart failure and 16 healthy controls. All patients underwent a metabolic assessment, which provided a measure of insulin sensitivity (intravenous glucose tolerance tests and minimal modelling analysis). Compared to controls, patients with chronic heart failure had significantly higher levels of circulating uric acid, interleukin-6, soluble tumour necrosis factor receptor (sTNFR)-1, soluble intercellular adhesion molecule-1 (ICAM-1, all P<0.001), E-selectin and sTNFR2 (both P<0.05). In patients with chronic heart failure, serum uric acid concentrations correlated with circulating levels of sTNFR1 (r=0.74), interleukin-6 (r=0.66), sTNFR2 (r=0.63), TNFa (r=0.60) (all P<0.001), and ICAM-1 (r=0.41, P<0.01). In stepwise regression analyses, serum uric acid emerged as the strongest predictor of ICAM-1, interleukin-6, TNF, sTNFR1 and sTNFR2, independent of diuretic dose, age, body mass index, alcohol intake, serum creatinine, plasma insulin and glucose, and insulin sensitivity. CONCLUSIONS: Serum uric acid is strongly related to circulating markers of inflammation in patients with chronic heart failure. This is consistent with a role for increased xanthine oxidase activity in the inflammatory response in patients with chronic heart failure