Abdoulaye Ba

Effects of hydration and water deprivation on blood viscosity during a soccer game in sickle cell trait carriers

The present study compared the changes in blood viscosity, hydration status, body temperature and heart rate between a group of sickle cell trait (SCT) carriers and a control (Cont) group before and after a soccer game performed in two conditions: one with water offered ad libitum (hydration condition; Hyd) and the other one without water (dehydration condition; Dehyd). Blood viscosity and haematocrit per blood viscosity ratio (HVR; an index of red blood cell oxygen transport effectiveness) were measured before and at the end of each game. Resting blood viscosity was greater in the SCT carriers than in the Cont group. The increase of blood viscosity over baseline at the end of the game in the Cont group was similar in the two conditions. In contrast, the change in blood viscosity occurring in SCT carriers during soccer games was dependant on the experimental condition: (1) in Dehyd condition, blood viscosity rose over baseline; (2) in Hyd condition, blood viscosity decreased below resting level reaching Cont values. The Cont group had higher HVR than SCT carriers at rest. HVR remained unchanged in the Cont group at the end of the games, whatever the experimental condition. Although HVR of SCT carriers decreased below baseline at the end of the game performed in Dehyd condition, it increased over resting level in Hyd condition reaching the values of the Cont group. Our study demonstrated that ad libitum hydration in exercising SCT carriers normalises the blood hyperviscosity.

Enhanced exercise-induced plasma cytokine response and oxidative stress in COPD patients depend on blood oxygenation

In healthy subjects, hypoxemia and exercise represent independent stressors promoting the exercise‐induced cytokine response and oxidative stress. We hypothesized that hypoxemia in patients with chronic obstructive pulmonary disease (COPD) may affect the cytokine production and/or the changes in oxidant–antioxidant status in response to maximal exercise. Exercise‐induced changes in PaO2 allowed to transiently increase or decrease baseline hypoxemia and to point out its specific action on muscle metabolism. COPD patients with severe to moderate hypoxemia (56 < PaO2 < 72 mmHg) performed an incremental cycling exercise until volitional exhaustion. Two cytokines [interleukin (IL)‐6 and tumour necrosis factor (TNF)‐α] and three blood indices of oxidative stress [plasma thiobarbituric acid reactive substances (TBARS) and two antioxidants, reduced erythrocyte glutathione (GSH), and reduced plasma ascorbic acid, RAA] were measured at rest, then during and after exercise. The changes in the cytokine levels and oxidant–antioxidant status were analysed in relation with the baseline PaO2 and its exercise‐induced variations. Data were compared with those obtained in an age‐ and body mass index‐matched group of healthy subjects. Compared with healthy subjects, COPD patients presented a marked accentuation of exercise‐induced increase in IL‐6 level and earlier changes in their oxidant–antioxidant status. Resting levels of IL‐6 and TNF‐α and exercise‐induced peak variations of TBARS, IL‐6 and TNF‐α were negatively correlated with the baseline PaO2. In COPD patients, the peak increases in IL‐6 and TBARS were attenuated when exercise hyperventilation reduced the baseline hypoxemia. Our study indicates that the PaO2 level affects both the exercise‐induced oxidative stress and cytokine response in hypoxemic COPD patients.

Intraday blood rheological changes induced by Ramadan fasting in sickle cell trait carriers.

The goal of the present study was to test whether fasting during the holy period of Ramadan may disturb blood rheology in sickle cell trait (SCT) carriers more than in a group of subjects with normal hemoglobin. Twenty African male students participated in the study: 10 SCT carriers and 10 subjects with normal hemoglobin (CONT). Biochemical parameters (plasma glucose and lipids levels), hematocrit, blood viscosity, and urine specific gravity were measured in the two groups on the 14th day of the Ramadan period (Ramadan condition) and 6 wks after the end of Ramadan (baseline condition). All the measurements were performed twice for each experimental day to measure intraday variation: 8:00 and 18:00 h. Plasma glucose level and lipid profile were not significantly different between the two groups. Although Ramadan did not affect the lipid profile, the plasma glucose concentration was lower during the Ramadan period compared with the baseline condition in the two groups. Hematocrit and urine specific gravity did not differ between the two groups and was greater in the evening than in the morning, independently of the condition. SCT carriers had higher blood viscosity than the CONT group. However, whereas blood viscosity remained unchanged through the day in the CONT group, whatever the condition, SCT carriers were characterized by a large increase of blood viscosity in the evening during the Ramadan period, indicating higher risk for microcirculatory blood flow impairments. Specific medical recommendations are needed for SCT carriers engaged in religious fasting.

[Evaluation of erythrocyte deformability in subjects with sickle cell trait during a soccer game: effect of hydration ad libitum].

This study compared erythrocyte changes between a group of subjects with sickle cell trait (SCT) and controls (subjects without hemoglobinopathy) during a soccer game in two conditions: with and without hydration. Erythrocyte deformability of subjects was assessed by the coefficient of erythrocyte rigidity (Tk) which was calculated before and after football match. Our results showed a significant increase in erythrocyte rigidity (Tk) in SCT at the end of physical activities without hydration; however when water was provided ad libitum their Tk decreased significantly, reaching values of controls. And adequate hydration is recommended in subjects with sickle cell trait during and after exercise.

Évaluation de la déformabilité érythrocytaire des sujets porteurs de trait drépanocytaire au cours d’un match de football : effet de l’hydratation ad libitum

This study compared erythrocyte changes between a group of subjects with sickle cell trait (SCT) and controls (subjects without hemoglobinopathy) during a soccer game in two conditions: with and without hydration. Erythrocyte deformability of subjects was assessed by the coefficient of erythrocyte rigidity (Tk) which was calculated before and after football match. Our results showed a significant increase in erythrocyte rigidity (Tk) in SCT at the end of physical activities without hydration; however when water was provided ad libitum their Tk decreased significantly, reaching values of controls. And adequate hydration is recommended in subjects with sickle cell trait during and after exercise.

Impact of exposure to biomass on the vascular function of Senegalese women

Background: In rural Senegal, biomass fuels are the main and often the only source of domestic energy for cooking. Their combustion is a source of particles and many other chemical contaminants that could alter cardiovascular function. Aims and Objectives: The aim of our study was to assess the effects of exposure to biomass fumes on vascular function in non-smoking women in rural Senegal. Materials and Methods: We conducted a cross-sectional 8-month study of 64 women (32 exposed to biomass smoke and 32 unexposed controls) who were active or housewives and involved in cooking. The subjects were aged 33.56 ± 9.34 years and 30.22 ± 6 years, respectively. All the women received a questionnaire with questions on sociodemographic characteristics, habitat characteristics, cooking habits, and biomass exposure conditions. Flow-mediated brachial arterial vasodilation flow-mediated dilatation (FMD) expressed as a percentage of the diameter was measured basally at rest and post-compression at 5, 30, 60, 90, and 120 s and 10 min after deflation. Results: All participants were non-smokers. 12.5% of subjects used gas in addition to biomass. Seniority was 18. 90 ± 10 years, with a mean daily biomass exposure of 4 ± 1 h. The analysis of cardiovascular parameters and blood sugar found no significant difference between the two groups. Kinetic FMD comparisons between the two groups showed significant differences at points 60 and 90 s 10 min post-occlusion. A negative correlation was found between FMD at 90 s after deflation and the duration of exposure in exposed women (r = 0.44 P < 0.05). Conclusion: Our results showed that exposure to biomass is implicated in the appearance of vascular dysfunction in non-smoking women.

Insulin resistance and arterial stiffness: impact of gestational diabetes on pulse wave velocity

Background: Gestational diabetes is an intolerance of glucose with the first appearance during the pregnancy. This hyperglycaemia status, because of the pre-existing insulin-resistance, constitute a favourable land of arterial stiffness. The aim of this study is to determine the impact of non obese gestational diabetes on arterial stiffness by measuring the pulse wave velocity (PWV). Methods: We recruited 60 pregnant women aged from 20 to 35 years old. They were between twentieth four and thirtieth five weeks of gestational age. Subjects were divided into two groups: the first group (G1), considered as control group, included 25 normoglycemic pregnant subjects without any history of illness or risk factors of gestational diabetes; the second group (G2) included 35 women with Gestational Diabetes Mellitus (GDM). All pregnant women had not history of smoking, were not taking decoction or medicine, which could disturb pregnancy evolution. Anthropo-physiological and biochemical parameters studied, were: age, body mass index (BMI), blood pressure (BP), triglyceride, cholesterol and HOMA-IR index. The PWV between finger and toe (PWVft) was measured by pOpmètre®. Results: The two groups are matched by age (G1:28±4ans; G2:29±3ans) and BMI (G1:25.6±1.27; G2:26.9±1.3). Blood pressure (BP) values are in normal interval (systolic BP: [110-132mmHg]; diastolic BP: [63-87mmHg]; mean BP: [79-103mmHg]). Total cholesterol (G1:0.95±0.08;G2:2.4±0.7; p˂0.0001), HDL cholesterol (G1:0.44±0.02; G2:0.76±0.2; p˂0.0001, LDL cholesterol (G1:0.40±0.05; G2:1.3±0.5; p˂0.0001), triglyceride (G1:0.57±0.45; G2:1.6±0.4;p˂0.0001), HOMA.IR (G1:1.31±1.05; G2:7.4±1.07; p˂0.01), PWVft (G1:5.99±1.23; G2:10.3±1.9; p˂0.0001) are significantly higher in diabetic group. PWVft is positively correlate to HOMA-IR index, total cholesterol, LDL cholesterol and triglycerides (r=0.3348, p=0.032; r=0.5275, p˂0.0001; r=0.4855,p˂0.0001; r=0.5581, p˂0.0001respectively). Conclusions: Gestational diabetes might induce an increase of pulse wave velocity expressing increment of arterial stiffness. This last constitute an early underlying cardiovascular risk.

Evaluation of vascular function in depigmented black women: Comparative study

Background: Prolonged application of skin depigmenting substances could expose human organism to serious general complications such as hypertension or diabetes. Artificial depigmentation (AD) is a widespread practice within Sub-Saharan Africa subjects. AD is based on the use of dermocorticoides which could lead to vascular complications. Aims and Objectives: Our aim was to evaluate the vascular function in depigmented Senegalese women. Materials and Methods: Thirty six depigmented (depigmented group) and 36 undepigmented black women (control group) participated in the study. They were aged 33.10 ± 7 years and 30.22 ± 6 years, respectively. Brachial artery flow mediated dilation (FMD) was measured in two groups. Biochemical and cardiovascular profiles of our study population were evaluated. The duration of depigmenting products exposure was evaluated in depigmented subjects. Results: Our study showed an abnormal kinetic of FMD in depigmented group compared to control group. Mean arterial pressure was 95.9 ± 8.8 mmHg in depigmented subjects and 89.6 ± 6.2 mmHg for control subjects and a significant difference was observed (P = 0.002) while triglycerides was significantly different (P = 0.01) between the two groups (0.8 ± 0.3 and 0.6 ± 0.2 g/L, respectively). FMD was significantly and positively correlated with exposure time (r = 0.25; P = 0.029). Conclusion: Prolonged percutaneous application of depigmentation products could alter metabolic and vascular functions, and consequently install cardiovascular risks. Thus, we recommended ways to prevent of AD in the African population.

Recovery of Body Composition after the Fasting of Ramadan in Young Sub-Saharan African Athletes

The fasting of Ramadan is causing circadian rhythm and body composition changes. It has been described a decrease of certain parameters during this period. Thus, the objective of our study was to evaluate the recovery of these parameters after the fasting of Ramadan. An experimental study was carried out among 18 students of the National Institute of Sciences of Physical Education and Sport (INSEPS) in Dakar. They were all male, black, aged 21 to 30 years and regularly practiced fasting. Data were collected on the 15th day of Ramadan and 6 weeks after Ramadan. Anthropometric and cardiovascular parameters were measured. Body mass index (BMI) was calculated from the anthropometric parameters such as weight and size by Quetelet’s formula. The parameters of body composition such as percentages of body fat, muscle mass and visceral fat were measured by an impedance meter (OMRON BF 511). Then, they allowed us to calculate percentage of fat free mass, fat free mass index (FFMI) and skeletal muscle mass index (SMMI). No significant difference was found for cardiovascular parameters between the two periods. However, certain parameters such as weight, BMI, fat mass, fat free mass and FFMI increased significantly six weeks after Ramadan. A strong trend of increasing was found in the percentage of fat mass (p = 0.05), while the percentage of muscle mass slightly tended to decrease after Ramadan. The principal component analysis showed that the percentages of body fat, fat free mass and muscle mass as well as fat mass were the most contributory parameters of the body composition in both times. The fasting of Ramadan causes transient changes in body composition. Long-term changes in certain parameters such as fat mass were necessary for a real effect on health. The association of Ramadan fasting with that of Sunnah would be necessary to obtain this benefit.

Cardiopulmonary Response to Exercise in COPD and Overweight Patients: Relationship between Unloaded Cycling and Maximal Oxygen Uptake Profiles

Cardiopulmonary response to unloaded cycling may be related to higher workloads. This was assessed in male subjects: 18 healthy sedentary subjects (controls), 14 hypoxemic patients with chronic obstructive pulmonary disease (COPD), and 31 overweight individuals (twelve were hypoxemic). They underwent an incremental exercise up to the maximal oxygen uptake (VO2max), preceded by a 2 min unloaded cycling period. Oxygen uptake (VO2), heart rate (HR), minute ventilation (VE), and respiratory frequency (fR) were averaged every 10 s. At the end of unloaded cycling period, HR increase was significantly accentuated in COPD and hypoxemic overweight subjects (resp., +14 ± 2 and +13 ± 1.5 min−1, compared to +7.5 ± 1.5 min−1 in normoxemic overweight subjects and +8 ± 1.8 min−1 in controls). The fR increase was accentuated in all overweight subjects (hypoxemic: +4.5 ± 0.8; normoxemic: +3.9 ± 0.7 min−1) compared to controls (+2.5 ± 0.8 min−1) and COPDs (+2.0 ± 0.7 min−1). The plateau VE increase during unloaded cycling was positively correlated with VE values measured at the ventilatory threshold and VO2max. Measurement of ventilation during unloaded cycling may serve to predict the ventilatory performance of COPD patients and overweight subjects during an exercise rehabilitation program.