Anaemia, renal dysfunction and in-hospital outcomes in patients with heart failure in Botswana.

BACKGROUND: Anaemia and renal dysfunction are associated with an increased morbidity and mortality in heart failure (HF) patients. OBJECTIVE: To estimate the frequency and impact of anaemia and renal dysfunction on in-hospital outcomes in patients with HF. METHODS: A total of 193 consecutive patients with HF admitted to Princess Marina Hospital, Gaborone, Botswana, from February 2014 to February 2015, were studied. Anaemia was defined as haemoglobin <13 g/dL for men and <12 g/dL for women. Renal dysfunction was defined by an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, calculated by the simplified Modification of Diet in Renal Disease formula. The in-hospital outcomes included length of hospital stay and mortality. RESULTS: The mean (standard deviation (SD)) age was 54.2 (17.1) years and 53.9% of the patients were men. The overall median eGFR was 75.9 mL/min/1.73 m2 and renal dysfunction was detected in 60 (31.1%) patients. Renal dysfunction was associated with hypertension (p=0.01), diabetes mellitus (p=0.01) and a lower haemoglobin level (p=0.008). The mean (SD) haemoglobin was 12.0 (3.0) g/dL and 54.9% of the patients were anaemic. Microcytic, normocytic and macrocytic anaemia were found in 32.1%, 57.5% and 10.4% of patients, respectively. The mean (SD) haemoglobin level for males was significantly higher than for females (12.4 (3.3) g/dL v. 11.5 (2.5) g/dL; p=0.038). Anaemia was more common in patients with diabetes (p=0.028) and in those with increased left ventricular ejection fraction (p=0.005). Neither renal dysfunction nor anaemia was significantly associated with the length of hospital stay or in-hospital mortality. CONCLUSION: Anaemia and renal dysfunction are prevalent in HF patients, but neither was an independent predictor of length of stay or in-hospital mortality in this population. These findings indicate that HF data in developed countries may not apply to countries in sub-Saharan Africa, and call for more studies to be done in this region.

Determinants of hyperleptinaemia in an African population.

OBJECTIVE: To examine the determinants for elevated plasma leptin concentration in normal weight (NW), obese (OB), and morbidly obese (MO) individuals in Tanzania. DESIGN: Cross-sectional epidemiological study, the CARDIAC study. SETTING: Three areas in Tanzania; Dar es Salaam, urban (U), Handeni, rural (R) and Monduli, pastoralists (P), in August 1998. SUBJECTS: Five hundred and forty five participants from a random sample of 600 people aged 46-58 years. MAIN OUTCOME MEASURES: Plasma leptin concentrations, height, weight, body mass index (BMI), lipid profiles, haemoglobin A1c (HBA1c), and blood pressure (BP). RESULTS: Plasma leptin concentrations were higher in women than in men (women; 16.0 ng/mL, men; 3.1 ng/mL; p<0.0001). Women showed a higher mean body mass index (BMI), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) than men. In both genders, plasma leptin concentration, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), systolic BP (SBP) and diastolic BP (DBP) were significantly higher in OB than in NW participants. MO women had significantly higher leptin concentration, SBP and DBP compared with the other two groups. In NW men, log leptin concentrations showed a direct correlation with weight, BMI, HBA1c, TC, LDL-C, TG, SBP and DBP (all p<0.0001 except TG; p<0.001), while among NW women and OB men, weight and BMI correlated positively with log leptin (all p<0.05). OB women observed a positive correlation between log leptin and weight, BMI and LDL-C. Regression analysis indicated that among NW subjects, gender, BMI and TC explained 53.9% of the variation in log leptin. In OB subjects, gender, BMI and LDL-C explained 51.7% of the variability in leptin levels. No relationship was found between log leptin and CVD risk factors among MO subjects. CONCLUSION: The most important determinants for hyperleptinaemia in NW participants were gender, BMI, TC, while in addition to these LDL-C, was an important determinant of leptin concentration in OB individuals. In MO women, the high leptin concentrations did not reflect the amount of adipose stores.

Obesity and lipid profiles in middle aged men and women in Tanzania.

OBJECTIVE: To examine the relationship between obesity and lipid profiles and to compare the effects of total obesity and central adiposity on lipids in three locations in Tanzania. DESIGN: Cross-sectional epidemiological study. SETTING: Three areas in Tanzania: Dar es Salaam (urban), Handeni (rural) and Monduli (pastoralists), in August 1998. SUBJECTS: Five hundred and forty five men and women from a random sample of 600 people aged 46-58 years. MAIN OUTCOME MEASURES: Mean BMI, waist circumference, WHR, TC, HDL-C, LDL-C, TG and LDL/HDL ratio. Prevalence rates of overweight,obesity, central obesity and dyslipidaemia. RESULTS: As compared to men, women had higher BMI (24.7 versus 22.5 kg/m2, p<0.0001), waist circumference (92.4 versus 89.1 cm, p<0.05), TC (4.9 versus 4.2 mmol/L, p<0.0001) and LDL-C (3.3 versus 2.6 mmol/L, p<0.0001). The urban population demonstrated higher levels of lipid factors than the rural population (TC, men 4.8 mmol/L; women 5.3 mmol/L, p<0.0001; TG, men 3.6 mmol/L; women 3.7 mmol/L, p<0.0001, LDL-C, men 2.8 mmol/L, p<0.0001). BMI and waist circumference correlated positively with serum TC, TG, and LDL-C in both genders. Stepwise regression analysis showed that BMI predicted triglyceride concentration in men (p<0.05) and women (p<0.0001). Waist circumference predicted levels of TC in women only (p<0.0001) and of LDL-C in both genders (men p<0.05, women p<0.0001). The prevalence of overweight, obesity and central obesity were significantly higher in urban than in rural areas in both men and women. Compared to lean subjects, obese men and women had significantly higher mean serum TC, TG, LDL-C and a higher prevalence of dyslipidaemia. The mean levels of TC, TG and LDL cholesterol increased across successive increases in BMI and waist circumference quintiles in both genders. CONCLUSION: Subjects from the urban area had greater lipid abnormalities related to obesity than those from the rural area and that, central adiposity had a greater effect on total cholesterol and LDL cholesterol among women than was BMI.

Cardiovascular risk factors in Tanzania: a revisit.

In this assessment of cardiovascular risk factors, we examined the prevalence of selected risk factors according to the World Health Organisation (WHO) CARDIAC Study protocol and compared them with a similar study conducted more than a decade ago. The survey was carried out in Dar es Salaam (D, urban), Handeni (H, rural) and Monduli (Mo, semi-nomadic area). Subjects aged 47-57 were recruited randomly for blood pressure and anthropometrical measurements, 24 h urine collection and blood sampling. A structured questionnaire was used to obtain dietary information. The 1998 survey studied 446 subjects, while the 1987 survey included 496 men and women. The measured weight, body mass index (BMI) and prevalence of obesity (BMI > or = 30 kg/m(2)) increased significantly among women in the 1998 survey in rural Handeni and urban Dar. The overall prevalence of obesity was higher for women in the most recent survey (22.8%, P < 0.0001). Diastolic blood pressure (DBP) was higher in the most recent survey for women in Handeni. The overall prevalence of hypertension (blood pressure > 160/95 mmHg, or antihypertensive drug use), rose to 41.1% in 1998, (P < 0.001) for men and to 38.7% (P < 0.05) for women. The mean total serum cholesterol and prevalence of hypercholesterolaemia increased significantly in the most recent survey in the three studied areas. The overall prevalence of hypercholestrolaemia (serum cholesterol > 5.2 mmol/l) was higher in the 1998 survey for both men (21.8%, P < 0.0001) and women (54.0%, P < 0.0001). The mean HDL cholesterol increased significantly in the most recent survey, with a significant reduction in the mean atherogenic index, though these were still at higher levels (men 5.8, P < 0.0001; women 5.1, P < 0.0001 vs. 1987). A strong positive correlation was observed between blood pressure (SBP and DBP) and body mass index, total serum cholesterol and sodium to potassium ratio. These data suggest that for the past decade there has been an increase in the mean levels and prevalence of selected cardiovascular risk factors in Tanzania.

The relation of oxidative DNA damage to hypertension and other cardiovascular risk factors in Tanzania.

OBJECTIVES: To clarify the mechanism of involvement of oxidative stress in hypertensives, we investigated the relationship between the marker of oxidative DNA damage, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and cardiovascular risk factors, such as hypertension and serum glycosylated hemoglobin (HbA1c), among Tanzanians aged 46-58 years who were not on antihypertensive medication. DESIGN AND METHODS: Sixty subjects (males/females, 28/ 32) were selected randomly from the subjects who completed a 24h urine collection in our epidemiological study at Dar es Salaam, Tanzania in 1998. The subjects were divided into two groups, hypertensive subjects (systolic blood pressure (SBP) > or = 140 mmHg and/or diastolic blood pressure (DBP) > or =90 mmHg) and normotensive subjects (SBP < 140 mmHg and DBP < 90 mmHg) or hyperglycemic subjects (HbA1c > or = 6.0%) and normoglycemic subjects (HbA1c < 6.0%). Biological markers from urine and blood were analyzed centrally in the WHO Collaborating Center. RESULTS: The mean levels of HbA1c and 8-OHdG were significantly higher in the hypertensive subjects than in the normotensive subjects (P < 0.05). Urinary 8-OHdG was significantly higher in hyperglycemic subjects than in normoglycemic subjects. HbA1c was positively correlated with the 24-h urinary 8-OHdG excretions (r= 0.698, P < 0.0001). CONCLUSIONS: These findings suggest oxidative DNA damage is increased in hypertensive subjects, and there is a positive correlation between the level of blood glucose estimated as HbA1c and oxidative DNA damage. Hyperglycemia related to insulin resistance in hypertension in Tanzania is associated with increased urinary 8-OHdG.

Normal peak expiratory flow in healthy adult male and female subjects.

Peak expiratory flows (PEF) were measured in 830 and 270 healthy male and female subjects respectively using Autospiro model AS-500 (Minato, Japan) fitted with a heated pneumotachograph. All measurements were made in the standing position. Male subjects gave significantly larger PEF values than female subjects (P < 0.001), and PEF decreased with age at a rate of about 6.45% year. In the female subjects, PEF increased with age to reach a peak at about 32 years decreasing thereafter. The equations representing peak expiratory flow for this population are: PEF = 0.042H - 0.051A + 3.5 (l.s-1) for the male subjects and PEF = 0.014H + 4.445 (l.s-1) for female subjects, where H and A represent height (cm) and age (years) respectively. Regression equations for predicting PEF constructed in this study gave smaller PEF values than values from prediction equation derived from a Caucasian population. It is therefore, highly desirable that equations suitable for predicting PEF in our region be established and more research in this area is required to cover some of the minority tribes in our region.

Validity of the forced rebreathing method in the measurement of residual volume in patients with airflow limitation.

The validity of the forced rebreathing method (FRM) in the measurement of residual volume (RVn) was assessed in two groups (28 and 12) of patients with significant airflow limitation. The mean FEV1% FVC% were 48.28%, SD = 8.91% and 54.3%, SD = 0.23% respectively. Patients performed at least 30 forced rebreathings into a bag and bottle system at about 28 breaths per minute. RVn per breath was regressed on breath and gas dilution was considered complete at the breath number where the regression line deviated from the nitrogen washout curve. Residual volume computed four breaths after the breath number where the regression line deviated from the curve were compared with results derived from helium dilution (RVHe), mouth (RVmo) and oesophageal (RVOeS) pressure changes in the body plethysmograph. The mean RVn was similar to RVHe (P > 0.98) and correlated well with RVHe (r = 0.908, P < 0.001). RVn and RVHe were significantly smaller than RVmo and RVoes (P < 0.001). The difference between RVn and RVmo was smaller than the difference with RVoes. RVmo was larger than RVoes (P < 0.001) and correlated well with RVoes (r = 0.939, P < 0.001). It is concluded that the FRM can be used with reasonable accuracy to measure residual volume in patients with airflow limitation, and has advantages over the plethysmographic and conventional helium dilution methods.

Changing relationship between FEV1 and height during adolescence.

Forced expired volume in one second (FEV1), body weight, standing and sitting height, and chest dimensions were measured in 962 male and 674 female subjects aged between 9 and 20 years. Standing height and body weight correlated best with ventilatory indices in boys. In girls, standing height, body weight and chest circumference correlated more or less equally with ventilatory indices. Regression analysis of logarithmically transformed FEV1 on standing height were done. In the boys, the correlation coefficient between In FEV1 and in height increased from 0.34 at 9 years to 0.77 at 13 years of age, while girls appear to have reached a peak by 12 years of age. The mean allometric constant was 3.109 and 3.032 for male and female subjects respectively. However, age-specific allometric constants increased in the boys from 2.846 to a peak value of 4.045 at 16 years of age. In the girls, the constant increased to a peak value of 4.5 a year earlier than in boys. The log-log plot of FEV1 against standing height was nonlinear, becoming more curvilinear with increasing height. These findings reflect changes in body proportions and shape during adolescence with lung growth lagging behind growth in standing height.

Single breath assessment of bronchial responsiveness: a comparison with the astograph method.

Bronchial responsiveness to inhaled doubling concentrations of acetylcholine using the astograph and single breath techniques was assessed in 7 males and 11 females (mean age 22.7, SD = 2.05 and 21.2, SD = 1.11 years for male and female respectively) healthy volunteers. Eleven (61%) of the subjects had neither a history of allergy nor wheezes. Five (28%) had allergic rhinitis and two (11%) had asthma. Seven (64%) of the normal subjects, all asthmatic and subjects with allergic rhinitis responded to inhaled acetylcholine. Respiratory conductance (Grs) and the one second forced expired volume (FEV1) expressed as percentages of the baseline values were compared on a semilogarithmic scale against cumulative dose. In most subjects the pattern of the curves showed close similarities in the two methods. The bronchial sensitivity i. e. minimum cumulative dose of acetylcholine just sufficient to start a fall in the FEV1 and Grs (CminS and CminA respectively), showed good correlation (r = 0.750, P less than 0.01). The results indicate that bronchial responsiveness can be reliably assessed using the simple single breath method as well as the more complex astograph method.

Predictions of normal forced vital capacity and forced expired volume in one second in Tanzanian children.

Data on ventilatory function with particular reference to forced vital capacity (FVC), forced expired volume in one second (FEV1), and FEV1 expressed as percentage of FVC (FEV1%FVC) were obtained in 1413 healthy Tanzanian school children aged between 8 and 18 years. All subjects were nonsmokers and had neither symptoms nor history of cardiopulmonary diseases. Subjects in this study were significantly smaller in stature (P less than 0.05) and had smaller FVC and FEV1 (P less than 0.001) compared to values reported in children of comparable age and stature in the west. Lung volumes could best be described as a power function of standing height (y = a.Hb). The power derived from ln FVC on ln H were 3.39 and 3.24 for boys and girls respectively, while the power derived from ln FEV1 on ln H were 3.11 and 3.03 for boys and girls respectively. Constructed prediction formulae gave FEV1 and FVC which showed good agreement with FEV1 and FVC computed from prediction equations based on a similar mathematical model for black children in the Caribbean.

Pulmonary function parameters in asthma patients receiving oral ketotifen.

Ketotifen, an antianaphylactic and antihistamine drug was given orally to 31 asthma patients who had significant airflow limitation (mean FEV1% FVC = 65.1). 19 patients had extrinsic asthma and 12 patients had intrinsic asthma. Ketotifen was given in a dose of 1 mg twice daily for 16 weeks. At the end of this period, concomitant medication, frequency and severity of asthma attacks and mean lung function test results were analysed. The number of acute asthmatic attacks were reduced significantly from a mean of 7.1 attacks/week before treatment to 0.28 attacks/week after 16 weeks of treatment (P less than 0.001). The severity of attacks and the need to use concomitant bronchodilators agents were also reduced. Lung function improved following oral ketotifen administration as indicated by changes in FVC, FEV1, FEV1% FVC and PEF. FVC increased insignificantly (18.64 ml/week, P less than 0.3), while FEV1, FEV1% FVC and PEF improved significantly (33.45 ml/week, 0.76%/week and 5.52 l/min/week respectively, P less than 0.01). It was concluded that the relief which is often observed in patients suffering from bronchial asthma on ketotifen therapy is associated with an improvement in the lung function. Hence, ketotifen is effective in the prophylaxis of both extrinsic and intrinsic asthma.