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

Autosomal Dominant Pattern of Inheritance in Type 2 Diabetes in Nigeria

We investigated 212 patients attending 3 diabetic clinics centres in Lagos; Nigeria; and recorded family history; age of onset of diabetes; and body mass index. Analysis of family pedigrees showed that 3of sibships followed an autosomal dominant pattern of inheritance. The mean age of diabetes onset among the dominant group was 25 years and obesity was uncommon. This suggests that these patients may have Maturity Onset Diabetes of the Young (MODY)

Prevalence of Risk Factors for Diabetes Mellitus in A Non-Diabetic Population in Jos; Nigeria

Background: Diabetes mellitus (DM) is assuming epidemic proportions worldwide; but probably more so in the developing world. Identification of risk factors for the development of type 2 diabetes mellitus is a necessary step in planning prevention programmes for diabetes mellitus. The objective of this study was to determine the frequency of risk factors for type 2 DM among inhabitants of Jos; a northern city on the Nigerian Plateau. Method: A district in central Jos was randomly picked. Census of the district was carried out to record the names of all eligible residents from 250 households selected systematically. A questionnaire was administered by trained interviewers. Socio-demographic data; family history of diabetes; and data on work related physical activity were recorded. Height; weight and waist and hip circumferences were also measured. BMI (kg/m2) and waist-hip ration were calculated. Results: Of 902 subjects (? 15years of age); 825 (91.5) responded. The mean (SD) age of 400 males and 422 females were respectively 36.4 (15.2) and 39.9 (17.3) years. About 50of the respondents were inactive. 435 (52.7) were currently taking alcohol. Twenty nine (3.5) of the subjects admitted to parental history of DM. 177 (21.4) were either overweight or obese. 32of males and 86of females had abnormal waist circumferences (WCE). 96 (23.8) males and 316 (74.9) females had abnormal WHR. BMI correlated strongly and significantly with WHR (r = 0.64; p 0.001) and WCE (r Conclusion: Inactivity; alcohol usage and excess weight appear to be dominant risk factors for development of type 2 DM in this group of upland Nigerians

Reduced Thyrotropin in Euthyroid Goitrous Patients Suggesting Subclinical Hyperthyroidism

B a c k g r o u n d : Subclinical hypertyhroidism; a biochemical finding of low serum thyrotropin (TSH) with the serum levels of thyroxine (T4 ) and triiodothyronine (T3) within the reference range; could easily be ignored by clinicians; as it; usually; does not manifest with any thyroid specific symptoms. It is of two types : endogenous and exogenous. However; patients with the findings of low TSH; normal T4 and T3 develop some abnormalities in the cardiovascular system; such as atrial fibrillation; increasein left ventricular mass and diastolic dysfunction. It is believed that treatment intervention may reduce or halt the progression of the cardiac abnormalities. The main objective of the study was to determine how frequent subclinical hyperthyroidism was occurs and to serve as a reminder to the existence of the disorder. Methods : It was a hospital-based study carried out at the Jos University Teaching Hospital (JUTH). Consecutive clinically euthyroid goitre patients attending the outpatient department of JUTH; were studied for various parameters including TSH; T4 and T3. The serum concentrations of T4 and T3 were determined by enzyme-linked immunosorbent assay (ELISA) technique. The serum TSH concentration was estimated using a 2nd generation ELISA technique. Results : 98 patients participated in the study. Nine patients had non-specific symptoms not referable to the thyroid and found to have high levels of thyroid hormone concentration with depressed TSH and were excluded from further analysis; while 7 had subclinical hyperthyroidism giving a prevalence rate of 7.9among these clinical euthyroid goitre patients. The subjects with this condition were mainly above 60 years of age and mainly had long-standing goitre. Conclusion: Endogenous subclinical hyperthyroidism was present in 7.9of these clinically euthyroid goitre patients mainly 60 years and above; with long - standing goitre. This high prevalence rate calls for high index of suspicion as this condition is associated with morbidities that can raise mortality

Effect of adding guar to some Nigerian meals on postprandial plasma glucose levels in non-insulin dependent diabetics

"The objective of this study was to determine the effect of adding a commercial fibre preparation to some common Nigerian meals on the plasma glucose response (PGR). Three popular Nigerian meals - yam flour (""amala""); rice; and cassava flour (""eba"") - were studied in non-insulin dependent diabetics by monitoring the PGR postprandially. Addition of guar resulted in varying degrees of suppression of PGR in the three meals tested. The differences between meals with guar and without guar in PGR indices were only significantly different in subjects who consumed the cassava flour preparation. It appears from this study that fibre-enrichment of some African diets can have beneficial effects in the control of diabetes in the African at least in the short term."

Effectiveness of different methods to eliminate interference by thyroglobulin antibodies in the ELISA for thyroid microsomal autoantibodies.

Thyroid microsomal autoantibodies (TMA) have been mostly detected by means of either immunofluorescence (IF), tanned red cell haemagglutination (TRCH), or radioimmunoassay (RIA) until the recent development of ELISA. False positives in the ELISA for the detection of TMA due to interference by thyroglobulin antibodies (TGA) present in some test sera reacting with thyroglobulin (Tg) present as a contaminant in the thyroid microsomal preparation (TMP) appears to be common. In this study we tried various ways of removing any Tg contaminant in the TMP by further gel filtration, affinity chromatography of the microsomal preparation or preincubation of the test sera with either Tg or Tg-sepharose 4B immunoadsorbent to absorb out TGA present in the sera. Further gel filtration and affinity purification of the TMP failed to totally remove all the contaminating Tg. Preincubation with Tg effectively removed any TGA present in the test sera but resulted in inhibition of the TMA-thyroid microsomal antigen reaction in the test sera including those without TGA. Preincubation with Tg-immunoadsorbent equally effectively absorbed out any TGA present in the test sera but without significant inhibition of the assay reaction in TGA-free sera. The preincubation of the TMP with Tg-immunoadsorbent is an effective way of removing TGA present in sera without inhibiting the test reaction and thus resulting in false negatives especially in low-titre sera as occurs with the presence of free Tg in the test system.