The prevalence and characteristics of latent autoimmune diabetes in adults subset among type two diabetes mellitus patients in Northern Nigeria.

INTRODUCTION: Latent autoimmune diabetes in adult (LADA) is a form of Type 1 diabetes mellitus (T1DM) that occurs in adult or with advancing age. It commonly occurs in people aged ≥30 years and is characterized by initial response to oral hypoglycemic agents, lean body mass, and presence of glutamic acid decarboxylase autoantibody (GAD-Ab). It exhibits rapid deterioration of the pancreatic β-cells secretory function due to the destructive action of the autoantibodies. The prevalence of LADA among T2DM patients varies among population due to different diagnostic criteria, patients' characteristics, the assay used, and genetic predisposition. In this study, we intend to document prevalence and clinical characteristics of LADA subset patients in Northern Nigeria.

METHODS: Two-hundred noninsulin-requiring T2DM patients were recruited from the diabetes clinic based on the selection criteria. Their clinical characteristics were documented, and we measured their serum GAD-Ab, glycated hemoglobin (HbA1c), fasting C-peptide, fasting plasma glucose, and fasting serum lipids. The mean (standard deviation) of these clinical and biochemical parameters was compared between GAD-Ab+ and GAD-Ab- groups. The data were analyzed using SPSS version 20 with P< 0.05 as statistically significant.

RESULTS: The prevalence of LADA among the T2DM patients studied was found to be 10.5% (21/200); there were more males than females (15 [71%]:6 [29%], χ2 = 4.2, P< 0.05). The mean age of the GAD-Ab+ was 52.0 (11.0), and there was no statistical difference with GAD-Ab- group. GAD-Ab+ was found more common in the age group of 40-49 years 10/21 (48%). The body mass index, waist circumference, and serum C-peptide were found to be significantly lower in GAD-Ab+ than in GAD-Ab- group (22.1 [51], 80.1 [12.4], 0.84 [0.05] vs. 27.3 [4.9], 93.2 [10.9], 1.72 [0.43]), P< 0.05. The HbA1c was found to be significantly higher in GAD-Ab+ than in GAD-Ab- (8.3 [1.4] vs. 7.0 [2.1]). Other clinical and metabolic parameters were found not to be significantly different between the two groups.

CONCLUSION: We conclude that the prevalence of LADA among T2DM patients in Northern Nigeria is 10.5%. It is more common among males aged 40-49 years and lean subjects. The male sex and decreasing central adiposity are predictors of GAD-Ab+ among T2DM subjects.