Dose-effect relation between regular consumption of 100% cocoa powder and blood pressure in young, healthy black Africans.

BACKGROUND: Some previous works have focused on dose-response relationship between cocoa consumption and blood pressure in Caucasians. As black subjects have lower nitric oxide bioavailability, the aim of this work was to determine the dose-effect relation between cocoa and blood pressure in black Africans. METHOD: One hundred and thirty healthy black African males aged 18-30 were randomly assigned into four groups: three groups consuming 10 g, 5 g, or 2 g of cocoa powder daily for three weeks and one control group that did not consume cocoa. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured on day 1 (D1, before any subject consumed cocoa), D8, D15, and D22. Means of the parameters at each of the four visits and changes of the means were compared among the groups. RESULTS: Significant decrease in SBP was noted in consumers of 10 g compared to controls in the 1st week, and compared to consumers of 2 g in the 2nd and 3rd weeks of follow-up. Means and changes of DBP were statistically similar among the four groups. CONCLUSION: Among our cohort, decrease in SBP was significantly greater in the heavy cocoa consumer group (10 g) compared to the low consumer group (2 g), but there was no statistically significant difference when compared with the intermediate consumer group (5 g). The dose-response relationship between cocoa consumption and changes in SBP was not linear. No relationship was found between cocoa consumption and DBP.

Weekly Physiological Changes in Blood Pressure During Three Weeks Daily Consumption of 10 Grams of Cocoa Powder Among Young Black Africans in Côte d'Ivoire.

BACKGROUND: In Caucasians, regular consumption of cocoa induces a drop in arterial blood pressure via an increase in nitric oxide (NO) production. However, black individuals have a different NO biodisponibility compared to Caucasians. The aim of this study was to determine, in black Africans, the physiological variations in arterial blood pressure among cocoa consumers. METHOD: In total, 49 male black African volunteers, aged between 18 and 30 years old, were randomized into two groups; those consuming 10 g of cocoa powder per day (1,680 mg of flavonoids per day) for 3 weeks (consumer group), and those not consuming cocoa (control group). Systolic (SBP) and diastolic blood pressures (DBP), and heart rate (HR) were measured in the morning on an empty stomach (fasting), on day (D) 1 (without cocoa), D8, D15, and D22. Data were collected by groups and by subgroups established according to the level of SBP, DBP, or HR on D1. The means and variations of the means (between D1 and the subsequent days) of the recorded parameters were calculated and compared between groups and between subgroups. RESULTS: On D8, the variations in SBP in the consumer group were significantly different from the control group (-3.72 ± 6.01 versus 0.57 ± 6.66 mmHg; p = 0.02). Between the control and consumer subgroups according to SBP, no statistical difference in the means or variations in SBP was noted. On D8 and D22, the variations in the SBP of consumers with SBP ≥ 110 mmHg on D1 were significantly different from those of other consumers (D8: -6.55 ± 5.96 versus -1.1 ± 4.93 mmHg; p = 0.01; D22: -6.63 ± 7.77 versus 0.35 ± 5.58 mmHg; p = 0.01). In the subgroups with a DBP < 75 mmHg on D1, the mean DBP of the consumers was significantly lower than that of the controls on D8 (65 ± 5 versus 69 ± 6 mmHg; p = 0.03). CONCLUSION: In young black African men living in Côte d'Ivoire, regular consumption of cocoa resulted in a decrease in SBP and DBP. The decrease in SBP appeared to be greater the higher the baseline SBP was.

Physiological variations of blood pressure according to gender and age among healthy young black Africans aged between 18 and 30 years in Côte d'Ivoire, West Africa.

In Africa, abnormal high blood pressure is common and affects young subjects. The risk of organ damage and mortality increases with blood pressure level. Therefore, the purpose of this study was to assess the blood pressure profile of a black African population aged between 18 and 30 years in Côte d'Ivoire. Five hundred fifty-one healthy black African students, men and women, with sedentary lifestyle, aged between 18 and 30 years were selected. Systolic (SBP) and diastolic (DBP) blood pressures and heart rate were recorded after 5 min of rest. Regression models were used to estimate the effects of age, gender, and body mass index (BMI) on SBP and DBP. Each increase of 1 year in age and 1 kg/m2 of BMI is significantly associated, respectively, with an increase of 20% (p = .002) and 17% (p = .008) in the risk of having an SBP ≥ 130 mmHg. The same risk is 3.8 times greater for men than women (p = .01). Among subjects with SBP < 120 mmHg, men have an SBP 5.22 mmHg higher than women (p < .001). The increase in the age of 1 year is significantly correlated with a rise of 36% of having a DBP ≥ 85 mmHg (p = .0001). Also, in men population, the age increase of 1 year is associated with a rise of 41% of having a DBP ≥ 85 mmHg (p = .0001). Among young black African students aged between 18 and 30 years in Côte d'Ivoire, SBP is positively associated with male gender, age, and BMI. For DBP, it is only an increase with age.

The PhysioFlow thoracic impedancemeter is not valid for the measurements of cardiac hemodynamic parameters in chronic anemic patients.

The aim of the present study was to test the validity of the transthoracic electrical bioimpedance method PhysioFlow® to measure stroke volume in patients with chronic anemia. Stroke volume index (SVI), as well as cardiac index (CI) obtained by transthoracic electrical bioimpedance method and doppler echocardiography were compared in healthy subjects (n = 25) and patients with chronic anemia (i.e. mainly with sickle cell anemia; n = 32), at rest. While doppler echocardiography was able to detect difference in SVI between the two populations, the Physioflow® failed to detect any difference. Bland & Altman analyses have demonstrated no interchangeability between the two methods to assess CI and SVI in anemic patients and healthy subjects. While doppler echocardiography displayed a good concordance for SVI results with those obtained in the literature for anemic patients, the Physioflow® did not. Finally, in contrast to doppler echocardiography: 1) the CI obtained with the Physioflow® was not correlated with the hemoglobin level and 2) the stroke volume determined by the Physioflow® was highly influenced by body surface area. In conclusion, our findings indicate that the Physioflow® device is inaccurate for the measurement of SVI and CI in patients with chronic anemia and has a poor accuracy for the measurement of these parameters in African healthy subjects.