Vitamin D supplementation improves insulin resistance in type 2 diabetes subjects in Lagos, Nigeria

Type 2 diabetes is a disease caused by both insulin resistance and an insulin secretory defect. Reports suggest that vitamin D3 supplementation improves insulin resistance and pancreatic beta-cell function, but there is paucity of data on vitamin D and glycaemia in type 2 diabetes in Nigeria. We have therefore performed a single blind prospective randomised placebo-controlled trial, involving type 2 diabetes participants in Lagos, Nigeria. The participants consisted of 42 type 2 diabetes patients with vitamin D deficiency. These participants were randomised into two equal groups of treatment and a placebo arm. Vitamin D3(3000 IU daily) was given to the participants in the treatment arm. Insulin resistance (HOMA-IR) and pancreatic beta-cell (HOMA-B) function were determined at baseline and after 12 weeks of vitamin D3 supplementation, or placebo treatment. There was a reduction from baseline in the mean insulin resistance level in both the treatment and placebo groups. How-ever, this reduction was only statistically significant in the treatment group (p <0.01). The proportion of subjects with improvement in insulin resistance status (homeostatic model assessment insulin resistance score (HOMA-IR)<2.0) was significantly higher in the treatment arm (p<0.05). There was a reduction in the mean insulin secretory capacity in the treatment group while it increased in the placebo group, though this difference was not statistically significant. We conclude that vitamin D3 supplementation results in a reduction in insulin resistance, but has no effect on pancreatic beta-cell function in type 2 diabetes

Comparison of low dose and standard dose adrenocorticotropin stimulation tests in healthy Nigerians

Hypothalamo-pituitary-adrenal (HPA) axis dysfunction is a potentially life-threatening condition. It is of paramount importance that safe; reliable diagnostic tests be available to identify patients at risk for adrenal insufficiency. The 250?g Adrenocorticotropic hormone (ACTH) stimulation test is commonly used to assess adrenocortical function. The 250?g dose is supraphysiological; therefore several investigators; over the years; have used 1?g ACTH stimulation test to assess adrenocortical function.The aim of the study was to compare the response of healthy adult Nigerian subjects to the 250?g and 1?g ACTH tests.Ten healthy subjects; five males and five females; aged between 20-60 years; (mean; 38.7 years) participated in this study. They all had normal medical histories and physical examinations; were nonsmokers; and had never received any type of glucocorticoid therapy. Serum chemistries; full blood counts; erythrocyte sedimentation rate; were all within normal limits. Both low dose ACTH test and standard dose ACTH test were performed on the 10 subjects in a randomized order on different days.There was no statistically significant difference in mean serum cortisol levels between the two test doses at 30 minutes (928.4 vs 929.8nmol/L). There was a strong correlation between 30-minute cortisol responses to 1?g and 250?g ACTH stimulation tests; r=0.999; p0.001.In agreement with other published data; our study confirms that 1?g ACTH stimulates adrenocortical secretion in normal subjects in the period 30 minutes post injection comparable to 250?g ACTH testing

Adrenocortical function in Nigerian patients with pulmonary tuberculosis (PTB)

Addison's disease was frequently consequent upon affectation of the glands by tuberculosis. Pulmonary Tuberculosis (PTB) is still very common in Nigeria but no report on the functional status of the adrenal cortex in patients with PTB in Nigeria exists. It is very important to note that subclinical adrenocortical failure in tuberculosis is an entity that should be considered as cortisol deficiency could be responsible for unexpected sudden death in this category of patients. This study sets out to determine the prevalence of subclinical adrenocortical failure in persons with PTB by determining the response to low-dose (1 ìg) ACTH stimulation. Forty four persons with newly diagnosed sputum-positive PTB and treatment naive, (23 males and 21 females, mean age 34.4 +/- 11.3 years, and mean body mass index (BMI) of 18.9 +/- 2.9 kg/m2) completed the study. Of the one hundred healthy volunteers recruited as control subjects, 70 persons (35 males and 35 females, mean age 38.1 +/- 12.5 years, BMI 24.1 +/- 3.7 kg/m2) completed the exercise. There was no statistically significant difference in the basal cortisol of healthy subjects and persons with PTB (239.9 vs. 229.1 nmol/L, p = 0.661). The thirty minute response to ACTH stimulation test and increment were significantly lower in persons with PTB than in healthy subjects. Adrenocortical insufficiency, mostly at the subclinical level, is common in persons with PTB infection, occurring in about 23% of patients. We therefore recommend that basal cortisol levels should not be used to detect adrenocortical insufficiency; rather stimulation tests should be used to exclude or confirm suspected adrenocortical insufficiency in patients with PTB

Trace mineral status and glycaemic control in Nigerians with type 2 diabetes

Diabetes has been shown to be associated with abnormalities in the metabolism of micronutrients, especially chromium, zinc, copper, magnesium, and manganese. People with type 2 diabetes attending the Diabetes Clinic of the University of Benin Teaching Hospital, were recruited to examine the relationship between trace mineral status and glycaemic control. A total of 120 persons were studied, mean (±SD) age was 54±7 years and mean duration of diabetes 4±4 years. Serum chromium level correlated inversely with fasting blood glucose (FBG) and HbA1c, unlike the serum concentration of zinc which had no significant correlation with either FBG or HbA1c. People with diabetes should be encouraged to eat local specific foods rich in chromium