Table 1. Characteristics of a South African bi-ethnic gender cohort.

	Africans	Caucasians
Variables	(n = 197)	(n = 209)	p-values
Confounders
Age(years)	44.4 ± 8.2	45.0 ± 10.9	0.49
Body mass index (kg/m2)	30.1 ± 7.0	27.6 ± 5.9	< 0.001
Body surface area (m2)	1.9 ± 0.2	2.0 ± 0.3	< 0.001
Physical activity (kcal/day)	2670 ± 794.4	3112 ± 1596.5	< 0.001
Cotinine (ng/ml)	27.5 ± 61.3	22.71 ± 77.5	0.5
γ-Glutamyl transferase (U/l)	66.3 ± 83.0	26.91 ± 33.9	< 0.001
Potential cardiometabolic risk markers
Cortisol (nmol/l)	358.03 ± 151.63	384.11 ± 159.9	0.093
BDNF (pg/ml)	1411.6 ± 652.3	1687.3 ± 888.1	< 0.001
Cortisol:BDNF ratio	126.6 ± 114.4	102.7 ± 71.6	0.012
C-reactive protein (mg/l)	8.55 ± 10.56	3.1 ± 3.88	< 0.001
Cholesterol (mmol/l)	4.6 ± 1.16	5.5 ± 1.28	< 0.001
HbA1c (%)	6.1 ± 1.2	5.5 ± 0.42	< 0.001
24-h SBP (mmHg)	133 ± 16	124 ± 12	< 0.001
24-h DBP (mmHg)	83 ± 11	77 ± 8	< 0.001
12-lead ECG HR (bpm)	68 ± 13	66 ± 11	0.003
Hypertension, n (%)	43 (26.54)	18 (9.33)	< 0.001
Medications
Hypertensive treatment, n (%)	69 (35.03)	27 (12.92)	< 0.001
Statins, n (%)	2 (1.23)	9 (4.67)	0.05
Diabetes medication, n (%)	10 (5.08)	2 (0.96)	0.01
CRP > 3 mg/l, n (%)	106 (65.35)	39 (20.97)	< 0.001
HIV status, n (%)	19 (9.5)	0	< 0.001

Values presented as arithmetic mean ± SD.

BDNF, brain-derived neurotrophic factor; HbA1c, glycated haemoglobin; 24-h hypertension (SBP ≥ 130 mmHg and/or DBP ≥ 80 mmHg); HR, heart rate;

CRP, C-reactive protein; physical activity, 24-h total energy expenditure, considering resting metabolic rate; n, prevalence (%).