Browsing by Author "Longo-Mbenza, Benjamin"

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    Iodine nutrition status in Africa: potentially high prevalence of iodine deficiency in pregnancy even in countries classified as iodine sufficient
    (Public Health Nutrition, 2021) Bitamazire Businge, Charles; Longo-Mbenza, Benjamin; Kengne, Andre Pascal
    To assess the burden of iodine deficiency in pregnancy in Africa using estimated pregnancy median urinary iodine concentration (pMUIC). Design: pMUIC for each African country was estimated using a regression equation derived by correlating the school-age children (SAC) median UIC (mUIC) and pMUIC from countries around the globe, and the SAC mUIC data for African countries obtained from the Iodine Global Network (IGN) 2017 and 2019 Score cards. Setting: Iodine deficiency was endemic in many African countries before the introduction of iodine fortification, mainly through universal salt iodisation programmes about 25 years ago. There is a scarcity of data on the level of iodine nutrition in pregnancy in Africa. Women living in settings with pMUIC below 150 μg/l are at risk of iodine deficiency-related pregnancy complications. Participants: Fifty of the fifty-five African countries that had data on iodine nutrition status. Results: A cut-off school age mUIC ≤ 175 μg/l is correlated with insufficient iodine intake in pregnancy (pregnancy mUIC ≤ 150 μg/l). Twenty-two African countries had SAC mUIC < 175 μg/l, which correlated with insufficient iodine intake during pregnancy (pMUIC < 150 μg/l). However, nine of these twenty-two countries had adequate iodine intake based on SAC mUIC. Conclusions: There is likely a high prevalence of insufficient iodine intake in pregnancy, including in some African countries classified as having adequate iodine intake in the general population. A SAC mUIC ≤ 175 μg/l predicts insufficient iodine intake among pregnant women in these settings.
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    Low serum triiodothyronine and potassium levels are associated with increased risk of eclampsia among women in the Eastern Cape Province of South Africa
    (Clinical and Experimental Obstetrics and Gynecology, 2022) Bitamazire Businge, Charles; Longo-Mbenza, Benjamin; Kengne, Andre Pascal
    There is paucity of data on the relationship between thyroid hormones, potassium and eclampsia. Moderate-to-severe iodine deficiency that worsens during pregnancy leads to decreased thyroid hormone output and bioavailability to the brain. Apart from metabolic functions, T3 and T4 are essential fast acting cytosolic and synaptosomal neural transmitters that also regulate neuronal excitatory-inhibitory mechanisms. T3 also regulates the Na + -K + -ATPase pump that maintains the membrane ionic gradient. Hence altered serum potassium, thyroxine and triiodothyronine levels could increase the risk of eclamptic seizures. Methods: Forty-five women with eclampsia, 45 severe preeclampsia and 90 normotensive pregnant controls were enrolled into this study. Levels of thyroid hormones, thyroglobulin and urine iodine concentration (UIC) were measured and compared between the three groups. Results: Eclamptic participants had significantly lower median serum potassium (K), triiodothyronine (FT3), urinary iodine concentration (UIC) but higher serum thyroglobulin (Tg) (K = 3.7 mmol/L; FT3 = 3.8 pmol/L; UIC = 69.5 μg/L; Tg = 39.0 μg/L) than normotensive pregnant controls (K = 4.3 mmol/L; T3 = 4.7 pmol/L; UIC = 169.5 μg/L; Tg = 19.5 μg/L) and participants with severe preeclampsia (K = 4.2 mmol/L; T3 = 4.4 pmol/L; UIC = 95.7 μg/L; Tg = 22.4 μg/L), p < 0.05. Low UIC, low serum T3 and potassium and elevated Tg were independent predictors of eclampsia. Conclusions: Women with iodine deficiency in pregnancy may be at increased risk of eclampsia secondary to the ensuing rapid peripheral turnover of thyroid hormones leading to hypothyroxinaemia and reduced triiodothyronine bioavailability to the central nervous system that can be exacerbated by hypokalaemia.