Sympathetic nervous activity, depressive symptoms, and metabolic syndrome in black Africans: The sympathetic activity and ambulatory blood pressure in Africans study

Figures & data

Table I.  Characteristics of the study sample (mean ± SD).

Variable	Black controls (n = 112)	Black Met-S (n = 82)	Caucasian controls (n = 131)	Caucasian Met-S (n = 75)
Age (years)	43.3 ± 7.8	45.6 ± 8.2^*	44.2 ± 10.9	45.7 ± 10.7
Sex (% men)	62.3	34.9^*	43.5	56.0^*
Smoking (%)	21.1	11.6	15.3	12.2
Degree educated (%)	36.3	36.8	63.6	62.3
Depressive symptoms
None (%)	28.2	12.0	49.3	46.7
Mild–moderate (%)	58.2	66.3	46.9	44.3
Severe (%)	13.6	21.7^*	3.8	9.3
Waist–hip ratio	0.85 ± 0.10	0.90 ± 0.10^*	0.84 ± 0.08	0.94 ± 0.09^*
Total cholesterol (mmol/l)	4.60 ± 1.19	4.60 ± 1.19	5.46 ± 1.26	5.70 ± 1.32^*
HDL cholesterol (mmol/l)	1.18 ± 0.36	1.05 ± 0.32^*	1.29 ± 0.40	1.05 ± 0.38^*
Triglycerides (mmol/l)	1.45 ± 1.55	1.41 ± 0.80	1.00 ± 0.64	1.53 ± 0.84^*
Fasting glucose (sodium fluoride) (mmol/l)	5.36 ± 1.43	5.99 ± 2.65^*	5.42 ± 0.50	6.04 ± 0.99^*
Resting diastolic BP (mmHg)	80.9 ± 10.8	82.2 ± 9.7	75.0 ± 8.3	79.9 ± 7.7^*
Diastolic BP stress response (mmHg)	11.8 ± 8.6	12.3 ± 9.6	8.8 ± 7.8	8.5 ± 6.7
Resting systolic BP (mmHg)	140.4 ± 19.2	142.5 ± 17.0	129.1 ± 13.6	134.6 ± 13.9^*
Systolic BP stress response (mmHg)	18.7 ± 14.7	21.5 ± 17.1	19.8 ± 13.2	18.6 ± 13.1

*p < 0.05 compared with control of own ethnicity, one–way ANOVA; BP, blood pressure; Met-S, metabolic syndrome; HDL, high-density lipoprotein.

Figure 1.  (a) Salivary MHPG response to the Stroop mental stress task in black Africans. Participants with metabolic syndrome (N = 82) and without (N = 112) are designated with solid and broken lines, respectively. Values are adjusted for age and sex, error bars are standard error of the mean. The post-stress MHPG concentration was significantly different between the groups using the t-test (p < 0.05). (b) Salivary MHPG response to the Stroop mental stress task in caucasians. Participants with metabolic syndrome (N = 75) and without (N = 131) are designated with solid and broken lines, respectively. Values are adjusted for age and sex, error bars are standard error of the mean.