Serum C-peptide assay of patients with hyperglycemic emergencies at the Lagos State University Teaching Hospital (LASUTH), Ikeja.

INTRODUCTION: HE are common acute complications of diabetes mellitus (DM) and include diabetic ketoacidosis (DKA), normo-osmolar hyperglycemic state (NHS) and hyperosmolar hyperglycemic state (HHS). They contribute a lot to the mortality and morbidity of DM. The clinical features include dehydration, hyperglycemia, altered mental status and ketosis. The basic mechanism of HE is a reduction in the net effective action of circulating insulin, resulting in hyperglycemia and ketonemia (in DKA) causing osmotic diuresis and electrolytes loss. Infection is a common precipitating factor. Measurement of serum C-peptide provides an accurate assessment of residual β-cell function and is a marker of insulin secretion in DM patients.

AIM AND OBJECTIVES: To assess the level of pancreatic beta cell function in HE patients, using the serum C-peptide.

METHODOLOGY: The biodata and clinical characteristics of the 99 subjects were collated using a questionnaire. All subjects had their serum C-peptide, glucose, electrolytes, urea, creatinine levels, urine ketones determined at admission. Results of statistical analysis were expressed as mean ± standard deviation (SD). A p value <0.05 was regarded statistically significant. Correlation between levels of serum C-peptide and admission blood glucose levels and the duration of DM respectively was done.

RESULTS: The mean age of the subjects was 51 (SD ± 16) years and comparable in both sexes. Mean duration of DM was 6.3 (SD ± 7.1) years, with 35% newly diagnosed at admission. The types of HE in this study are: DKA (24.7%), NHS (36.1%), and HHS (39.2%). Mean blood glucose in this study was 685 mg/dL, significantly highest in HHS and lowest in NHS. Mean serum C-peptide level was 1.6 ng/dL. It was 0.9 ng/dL in subjects with DKA and NHS while 2.7 ng/dL in HHS (p>0.05). Main precipitating factors were poor drug compliance, new-onset of DM and infection.

CONCLUSION: Most (70%) of subjects had poor pancreatic beta cell function, this may be a contributory factor to developing HE. Most subjects with high C-peptide levels had HHS.