Correlates of left ventricular mass in hypertensive Nigerians: an echocardiographic study.

BACKGROUND: Studies have shown that left ventricular mass, diagnosed by echocardiography, correlated poorly with blood pressure, even when the 24-hour ambulatory blood pressure monitoring was taken into account in the analysis. This may be partly because there are other determinants of left ventricular mass such as age, gender, neurohormonal factors and heredity. Knowledge of the correlates of left ventricular mass could help design individual and population strategies to prevent or reverse left ventricular hypertrophy. To the best of our knowledge, there is a paucity of such studies in native Africans. Hence the purpose of this study was to define the correlates of left ventricular mass in hypertensive Nigerians. METHODS: The study was a retrospective analysis of prospectively collected data in 285 hypertensive subjects. Echocardiographic left ventricular mass was determined using the standard formula. Stepwise multiple regression analysis was used to determine the independent predictors of left ventricular mass with a probability value to enter and remove of p < 0.05. RESULTS: There were 153 men (53.7%) and 132 women (46.3%) in the study. The mean age of all subjects was 58.2 +/- 13.7 years. There was no significant gender difference in most of the echocardiographic parameters. In a stepwise multiple regression analysis, left ventricular wall tension, left ventricular wall stress, left atrial size, diastolic blood pressure, alcohol consumption and a family history of hypertension were the independent predictors of left ventricular mass in this population. The optimum multivariate linear regression main effects had an adjusted model, r(2) of 0.945, thus explaining about 95% of left ventricular mass variability. CONCLUSION: Mechanical or haemodynamic factors possibly interacting with genetic and social factors are the likely determinants of left ventricular mass in hypertensive Nigerians. Therefore modulation of some of these factors pharmacologically or non-pharmacologically will be of benefit in the management of this patient population.

Prevalence of refractive error and attitude to spectacle use among drivers of public institutions in Ibadan, Nigeria.

BACKGROUND: High rate of motor vehicle accidents' have been associated with poor vision. Studies on drivers from elsewhere other than health institutions have found abnormal visual acuities. The aim of this study is to determine prevalence of refractive errors and the attitude to spectacle wear among drivers of public institutions studied. METHODS: A cross sectional population study of all 99 motor vehicle drivers from the College of Medicine, University of Ibadan and University College Hospital (UCH) Ibadan between December 2003 and January 2004. RESULTS: The ninety-nine motor vehicle drivers in the study comprised of 67 (67.7%) from the College of Medicine, and 32 (32.3%) from the UCH. All were males, aged 38 to 60 years, mean 50.1 +/- (SD= 4.8 years). Proportion of drivers with refractive errors was 16.7% (95% CI, 16.6-16.8) but only 56.3% of these wear glasses while driving (others did not including 3 out 4 who were bilaterally visually impaired without glasses). Relative frequency of RTA among drivers was 16.2%, the risk was marginally higher among drivers with refractive error (OR 1.2, 95% CI: 0.4-3.7). The commonest refractive error was simple hypermetropia present in 15 eyes. Hypermetropia was associated with increasing age of drivers (p<0.05). Majority (97.7%) of the drivers were presbyopic but only 32 (32.3%) were current wearers of spectacles. CONCLUSION: Refractive errors were present in 16.7% of drivers studied. But 43.8% of these (3 out 4 of whom were bilaterally visually impaired without glasses) do not wear corrective lenses while driving. There is need for periodic visual screening exercise and eye health education on drivers.

Predictors of the failure of treatment with pyrimethamine-sulfadoxine in children with uncomplicated falciparum malaria.

The prevalence of pyrimethamine-sulfadoxine (PS)-resistant Plasmodium falciparum malaria has been increasing in sub-Saharan Africa or other parts of the world in the last one or two decades. The factors that identify children at risk of treatment failure after being given PS were evaluated in 291 children with acute, symptomatic, uncomplicated, P. falciparum malaria. The children took part in four antimalarial drug trials between July 1996 and July 2004 in a hyperendemic area of southwestern Nigeria. Following treatment, 64 (22%) of 291 children failed treatment by day 7 or 14. In a multivariate analysis, an age < or = 1.5 years (AOR=2.9, 95% CI 1.3-6.4, P = 0.009) and presence of fever (AOR = 3.3, 95% CI 1.28-7.14, P = 0.01) were independent predictors of the failure of treatment with PS at presentation. Following treatment, delay in parasite clearance >3 days (AOR = 2.56, CI 1.19-5.56, P = 0.016) was an independent predictor of the failure of treatment with PS. In addition, compared with the children who had no fever then, children with fever three or more days after starting treatment were more likely to be treatment failures. These findings may have implications for malaria control efforts in some sub-Saharan African countries where treatment of malaria disease depends almost entirely on PS monotherapy, and for programmes employing PS or PS-based combination therapy.

Effects of antifolates--co-trimoxazole and pyrimethamine-sulfadoxine--on gametocytes in children with acute, symptomatic, uncomplicated, Plasmodium falciparum malaria.

Antimalarial drugs including the antifolate, pyrimethamine-sulfadoxine (PS), can modulate the prevalence and intensities of gametocytaemia following treatment of acute malaria infections. They may also directly influence the transmission and spread of drug insensitivity. Little is known of the effects of co-trimoxazole (Co-T), another antifolate antimalarial, on gametocytes in children with acute malaria infections. We compared the effects of Co-T and PS on the prevalence and intensities of gametocytaemia and gametocyte sex ratios in 102 children aged 0.5-12 years presenting with acute and uncomplicated falciparum malaria. Compared to pre-treatment, both drugs significantly increased gametocyte carriage post-initiation of treatment. However, gametocyte carriage was significantly lower on day 14 in those treated with Co-T than PS. Significant increase in gametocytaemia with time occurred in PS--but not Co-T-treated children. Kaplan-Meier survival curve of the cumulative probability of remaining gametocyte-free in children who were agametocytaemic at enrollment showed that by day 7 of follow up, children treated with PS had a significantly higher propensity to have developed gametocytes than in Co-T-treated children (Log-rank statistic 5.35, df = 1, P = 0.02). Gametocyte sex ratio changes were similar following treatment with both drugs. PS and Co-T treatment of acute malaria infections in children from this endemic area is associated with significant increases in prevalence and intensities of gametocytaemia but these effects are more marked in those treated with PS than Co-T.

Effects of antifolates - co-trimoxazole and pyrimethamine-sulfadoxine - on gametocytes in children with acute, symptomatic, uncomplicated, Plasmodium falciparum malaria

Antimalarial drugs including the antifolate, pyrimethamine-sulfadoxine (PS), can modulate the prevalence and intensities of gametocytaemia following treatment of acute malaria infections. They may also directly influence the transmission and spread of drug insensitivity. Little is known of the effects of co-trimoxazole (Co-T), another antifolate antimalarial, on gametocytes in children with acute malaria infections. We compared the effects of Co-T and PS on the prevalence and intensities of gametocytaemia and gametocyte sex ratios in 102 children aged 0.5-12 years presenting with acute and uncomplicated falciparum malaria. Compared to pre-treatment, both drugs significantly increased gametocyte carriage post-initiation of treatment. However, gametocyte carriage was significantly lower on day 14 in those treated with Co-T than PS. Significant increase in gametocytaemia with time occurred in PS - but not Co-T-treated children. Kaplan-Meier survival curve of the cumulative probability of remaining gametocyte-free in children who were agametocytaemic at enrolment showed that by day 7 of follow up, children treated with PS had a significantly higher propensity to have developed gametocytes than in Co-T-treated children (Log-rank statistic 5.35, df = 1, P = 0.02). Gametocyte sex ratio changes were similar following treatment with both drugs. PS and Co-T treatment of acute malaria infections in children from this endemic area is associated with significant increases in prevalence and intensities of gametocytaemia but these effects are more marked in those treated with PS than Co-T.

Prevalence of rubella antibody in pregnant women in Ibadan, Nigeria.

BACKGROUND: There is a dearth of information on the incidence and prevalence of rubella infection in Nigeria. The risk of congenital rubella in sero-negative pregnant women has been found to produce congenital abnormalities even in developed countries. OBJECTIVE: The aim of this study is to determine the prevalence of rubella virus antibody in pregnant women. SETTING: The place of study is the antenatal care clinic of Adeoyo State Hospital, Ibadan. DESIGN: This is a cross-sectional study of primigravida women attending the antenatal care facilities in a general hospital The rubella IgG antibody of the women was detected in sera using the RUB IgG Test kit. This is a quantitative ELISA technique. RESULT: The prevalence of rubella antibody in 159 pregnant women that participated in this study was 68.5% with a confidence interval of 64.8% - 72.2%. Women living in rural -urban areas have statistically significant higher prevalence of antibody than those in urban areas. CONCLUSION: This prevalence of rubella antibody in pregnant women suggests 1 in 4 pregnant woman is susceptible and the foetus at risk of congenital rubella malformation.

Profile of some risk factors for coronary heart disease in a developing country: Nigeria.

The profile of some risk factors for coronary heart disease was studied in 557 male and 325 female Nigerians aged 20 years and above from the low and medium income groups, respectively. Except for the weight of subjects in the low income level, values of all physical characteristics were significantly higher in females than males (P < 0.01). In the 20-39 years age group, the systolic blood pressure was higher in males than females, and among the medium income group than the low income group (P < 0.01); but this difference disappeared in the higher age groups. The mean diastolic blood pressure was higher (but not statistically significant) at medium income levels than low income levels (P > 0.05). In each age group, the mean plasma total cholesterol was significantly higher in the medium income group than in the low income group (P < 0.01). The percentage of smokers and alcohol consumers were higher in the high income group than the low income group (P < 0.01). A high percentage of the smokers and alcohol consumers were male subjects. Blood pressure was correlated with age, smoking and body fat, (P < 0.01). Waist to trochanter ratio, and percentage body fat were significantly related to plasma total cholesterol level (P < 0.01).

Toxoplasmosis: antitoxoplasma IgG antibody levels in patients with lymphoid neoplasia in Ibadan, Nigeria.

The serum samples of 50 patients with lymphoid neoplasia, and of 112 control subjects from the normal population were analysed for the presence of antitoxoplasma IgG antibodies by the enzyme-linked immunosorbent assay technique. There was no significant difference between the prevalence rate of antitoxoplasma IgG antibodies in the control subjects (69%) and the patients with lymphoid neoplasia (66%). The prevalence of antitoxoplasma IgG antibody levels of 75 international units (i.u.) per ml and above was significantly higher in the patients (48%) than in the control subjects (18%). Antitoxoplasma IgG antibody levels of 150 i.u. and above per ml indicating active toxoplasmosis were present in 13 (26%) out of the 50 patients with lymphoid neoplasia. None of the sera from the control subjects had antitoxoplasma IgG antibody level up to 150 i.u. per ml of serum.

Serum cholesterol and diseases in Nigerians.

A study of 3451 cholesterol determinations in different diseases was carried out. The mean cholesterol levels for male and female adults and children with different diseases were compared with values for their healthy counterparts. Sickle cell anemia, leukemia, liver cirrhosis, hepatosplenomegaly, tuberculosis, and diabetic, nutritional, ataxic, and tropical neuropathies in male and female adults were associated with reduced cholesterol level while in children malnutrition and anemia were the main causes of low cholesterol levels. Obesity and hypertension caused an elevated level but the mean values were within the range for adult Nigerians in the high income group. Only nephrotic syndrome in both adult and children was associated with a markedly increased cholesterol level in Nigerians of low income status.