Assessment of the skeletal health of healthy Nigerian men and women using quantitative ultrasound.

The dietary intake of calcium by African populations, particularly in sub-Saharan Africa, is relatively low compared to the recommended intake for US adults. However, the rate of osteoporotic fractures in West African women is reported to be less than that for Caucasian populations. Because there is little published data regarding the skeletal status of African men and women, we used quantitative ultrasound (QUS) to assess the bone density of 435 Nigerian women and 321 Nigerian men between 16 and 89 years of age. A progressive decline in bone quality was observed beginning at about 40 years of age for both men and women. The mean stiffness index (SI) for the women between 20 and 35 years of age (n = 186) in this study was 102 +/- 17. The equation that best described the age versus SI relationship for women was SI = 79.7 + 1.887 (age) + -0.043 (age)2 + 0.00020 (age)3. For Nigerian men, the peak SI of 115 +/- 17 was seen in the 20- to 29-year-old age group. For men, the SI values remained above 100 until about age 60 years when a significant decline in SI was then observed. The best-fit curve of SI versus age for men was SI = 134.9 - 1.27 (age) + 0.019 (age)2 - 0.00014 (age)3. The broadband ultrasound attenuation (BUA), speed of sound (SOS), and SI values for the Nigerian men and women were comparable to or higher than those reported for Caucasian and Asian populations. These data should serve as reference values for adult men and women in sub-Saharan Africa.

Glucose metabolism among Norplant users in northern Nigeria.

Twenty-one women who were consecutive acceptors of Norplant were recruited for this study in our centre in August 1997. The patients had baseline (pre-insertion) investigations including a standard oral glucose tolerance test (OGTT). At their regular 3, 6, and 12 months follow-up visits, the OGTT was repeated and results were analyzed. The mean age of the clients was 31.3+/-4.51 years (range 24-40 years). The mean weights were 61.60+/-11.35, 57.63+/-7.51, 62.60+/-11.98, and 62.17+/-11.56 kg at pre-insertion, 3, 6, and 12 months follow-up visits respectively. The differences were statistically insignificant. All OGTT values at pre-insertion and at the follow-up visits were within the normal range. However, in comparison to pre-insertion levels (4.00+/-0.10 mmol/L), the fasting blood glucose concentration at 12 months (3.39+/-0.12 mmol/L) showed a statistically significant decline (p <0.001). The area under the glucose curve (AUC) rose by 5.8% (p = 0.018) at 3 months but declined by 5.8% (p = 0.110) and 7.3% (p = 0.103) at 6 and 12 months, respectively. The peak pre-insertion plasma glucose level following OGTT occurred at 30 min. At 3 months, the peak OGTT glucose level occurred at 30 minutes and plateaued until 60 min while at 6 and 12 months this occurred at 60 and 90 minutes, respectively. The overall trend of OGTT results within the study period showed that 12 months of Norplant use in Northern Nigerian women has no detrimental effect on glucose metabolism.

Comparison of the OptiMAL rapid test and microscopy for detection of malaria in pregnant women in Nigeria.

Malaria during pregnancy causes anaemia in pregnant women and low birthweight in infants. The purpose of this study was to evaluate the OptiMAL rapid malaria test in comparison with standard microscopy for malaria diagnosis in 268 pregnant women attending antenatal clinics at the Jos University Teaching Hospital and the Federal Medical Centre-Gombe in Nigeria. Positive results by either method were confirmed using a polymerase chain reaction assay for malaria. Although the OptiMAL assay did not detect malaria in the blood of pregnant women with low levels of parasitaemia, it may be useful for the detection of placental malaria which predisposes to low birthweight infants.

Assessment of the bone status of Nigerian women by ultrasound and biochemical markers.

Ultrasound analysis of the calcaneus and serum markers of bone turnover were used to examine the bone status of healthy Nigerian women who reside in an area of the world where dietary calcium intake is generally low and estrogen replacement therapy is not widely available. A total of 218 women (108 premenopausal and 110 postmenopausal) between the ages of 16 and 95 years were enrolled in the study. Broadband ultrasound attenuation (BUA) and speed of sound velocity (SOS) were measured and used to calculate the stiffness index (SI) of the calcaneus. In this cross-sectional study, the Nigerian women exhibited a marked age-dependent decline in SI that was defined by the regression equation SI = 105.9 - 6.62E-3 x Age2. SI was significantly correlated with age (r = -0.41, P < 0.001) and with serum NTx concentrations (r = -0.26, P < 0.001), but not with serum levels of bone-specific alkaline phosphatase (BSAP). Years since menopause was also significantly correlated with SI (r = 0.40, P < 0.001). A significant increase in serum NTx concentration occurred at least a decade before a significant decline in SI was evident. In the total study group, 24% of the women had T-scores indicative of osteopenia and 9% had T-scores indicative of osteoporosis, based on US reference data. Although the reported current incidence of fracture is low in women in sub-Saharan West Africa, these data show that after menopause Nigerian women have a decline in bone quality and increase in bone turnover similar to North American Caucasian women.