Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults

Simple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD riskPeer reviewedFinal Accepted Versio

Endothelial activation and cardiometabolic profiles of treated and never–treated HIV infected Africans

The role the human immunodeficiency virus (HIV) and antiretroviral treatment on endothelial activation, and the subsequent relationship with cardiovascular disease, is not well understood. We investigated endothelial activation, inflammatory and cardiometabolic profiles, and measures of vascular structure and function of 66 antiretroviral treated (ART), 78 never-treated (no-ART) HIV infected and 165 HIV free Africans. Methods Blood samples were obtained for biochemical analysis and blood pressure, pulse wave velocity (PWV) and carotid intima-media thickness (IMT) measurements were performed. Results The HIV infection duration was at least five years and the treatment 2.86 ± 0.13 years. The intracellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) levels were elevated in the HIV infected groups compared to the controls. The odds of higher adhesion molecule levels were increased when HIV infected (especially in the no-ART group); OR no-ART vs. no-HIV: ICAM 3.92 (2.2–7.0); VCAM 16.2 (7.5–35). ICAM and VCAM associated with HIV status and interleukin-6 (IL-6) in the total group (all p < 0.01). In both HIV infected groups VCAM associated inversely with CD4 counts (no-ART: β = −0.28, p = 0.01; ART: β = −0.22, p = 0.07) and TC (no-ART: β = −0.36, p < 0.01; ART: β = −0.27, p = 0.03). The ART group had an unfavourable lipid profile compared to the no-ART group. The inflammatory markers (C-reactive protein (CRP) and IL-6), PWV and IMT did not differ between the three groups. Conclusion HIV infected Africans showed endothelial activation when compared to HIV free controls. The endothelial activation was not accompanied by increased inflammation (as measured with CRP and IL-6), arterial stiffness or sub-clinical atherosclerosis

Defensive active coping facilitates chronic hyperglycaemia and endothelial dysfunction in African men: the SABPA study

Background: Dissociation between behavioural defensive active coping (AC) control albeit physiological “loss of control” responses was associated with silent ischaemia and structural wall abnormalities in African men. Whether it applies to structural alterations and endothelial dysfunction is uncertain. We therefore aimed to determine AC ethnic-gender specific receiver operating characteristic (ROC) carotid intima media far wall (CIMTf) cut points best associated with 24-h BP, -silent ischaemia and glycated haemoglobin (HbA1c). Methods: Participants included African and Caucasians (N=317) without pre-existing stroke or atrial fibrillation, aged 45±9 years. The Coping Strategy Indicator was used to measure AC. Ultrasound CIMTf, ambulatory BP, silent ischaemia and fasting blood samples were obtained. Results: Between 69 and 77% of AC African men showed above normal diastolic BP and HbA1c levels compared to 44–48% of AC Caucasian men. In AC African women, 41–60% showed above normal BP, silent ischaemia and HbA1c levels compared to 17–44% of their Caucasian counterparts. ROC curve analyses, detecting optimal CIMTf cut points, ranged between 0.57 and 0.65 mm (BP) and 0.71 and 0.74 mm (silent ischaemia) in AC ethnic-gender groups. Only HbA1C (>5.7%), with a sensitivity/specificity 47%/74%, after controlling for confounders, predicted structural alterations at an optimal cut point of 0.69 mm in AC African men (OR 4.5; 95% CI 2.93–18.73). Conclusion: Novel findings of behavioural resilience were apparent in the AC African female despite a high prevalence of risk markers. In AC males, chronic hyperglycaemia facilitated endothelial dysfunction, i.e. a physiological “loss of control” and susceptibility to stroke risk

Defensive coping facilitates higher blood pressure and early sub–clinical structural vascular disease via alterations in heart rate variability: the SABPA study

Objectives: Defensive coping (AC) responses in urban African males have been associated with vascular responsiveness, partly explaining autonomic nervous system dysfunction. We therefore aimed to assess whether AC responses facilitate higher blood pressure and early sub-clinical structural vascular disease via alterations in frequency- and time-domain heart rate variability (HRV) responses. Methods:We included 355 African and Caucasian men and women without pre-existing atrial fibrillation, aged 45 9 years. Significant interaction on main effects (coping ethnicity gender) for left carotid intima media thickness far wall (L-CIMTf) and cross sectional wall area values necessitated selection of AC responders above mean via the Coping Strategy Indicator. We collected B-mode ultrasound L-CIMTf, ambulatory BP andeHRV data. Overnight fasting blood was obtained. Results: Overall, Africans and AC Africans, mostly men, revealed a poorer lifestyle profile, higher prevalence of hypertensive status, disturbed sympathovagal balance and depressed HRV temporal and geometric patterns compared to the Caucasians (P 0.05). Moderately depressed non-linear and timedomain HRV (SDNN <100 ms) was prevalent in 28% of Africans compared to 11% of Caucasians. A similar trend was shown for the AC African participants (32%) compared to Caucasians (16%). Only depressed HRV time-domain (SDNN: adj. R2 ¼ 0.34; b ¼ 0.24; p ¼ 0.08) and vagal-impaired heart rate responses (RMSSD: adj. R2 ¼ 0.28; b ¼ 0.28; p < 0.05) were associated with higher blood pressure and early structural vascular changes in AC African men. Conclusion: Defensive coping facilitated autonomic nervous system dysfunction, which was associated with higher blood pressure and sub-clinical structural vascular disease in an African male cohort.http://www.journals.elsevier.com/atherosclerosis