Microalbuminuria : An Early Marker for Chronic Kidney Disease among Juvenile Diabetics : A Study

INTRODUCTION: Type 1 Diabetes mellitus is a chronic metabolic syndrome characterized by hyperglycemia as a cardinal biochemical feature due to deficient insulin secretion. It is the most common endocrine – metabolic disorder of childhood and adolescence , with important consequences of physical and emotional development. Morbidity and mortality stem from acute metabolic derangements and from long term complications that affect small and large vessels resulting in retinopathy,nephropathy,neuropathy,ischemic heart disease and arterial obstruction. Diabetic nephropathy accounts for significant reduction in life expectancy of diabetic patients. It is the leading cause of end stage renal disease and accounts for 50 % of deaths.The progression of diabetic nephropathy from the appearance of clinical proteinuria to end stage renal failure is usually irreversible without any intervention. Approximately 80% type 1 diabetic patients with persistent microalbuminuria develop overt nephropathy after 10 to 15 yrs. Eventually 50% of these develop end stage renal disease within 10 yrs and 75% by 20 yrs. AIMS AND OBJECTIVES OF THE STUDY: 1. To estimate the prevalence of microalbuminuria in type 1 diabetic patients ≤ 18 yrs of age attending diabetology clinic, Govt Rajaji Hospital, Madurai. 2. To study the associated risk factors in the development of microalbuminuria. DISCUSSION: The total no of cases enrolled in our study were 57, out of which 30 were females and 27 were males. The cumulative prevalence of microalbuminuria in our study was 12.28 %. The studies done by Jorner et al in 1992, Patel et al in 1998 and Schaltz et al in 2001 also showed the prevalence of microalbuminuria to be 12.50% similar to our study .The prevalence of microalbuminuria in type I diabetic children in different studies ranged between 7% and 28.2%. The wide range of prevalence in various studies may be due to difference in ethnic groups (genetic factors are believed to be responsible for the development of diabetic nephropathy), methodology and definition of microalbuminuria, population size, length of follow up and mean age of study population. SEX : Male to female ratio in our study is 1 : 2.5 . The higher incidence of microalbuminuria in females is also found in other studies – 1 : 1.9 in MIDAC and Pittsburg research groups(106,107) confirming that the development of microalbuminuria is accelerated in girls. AGE: The mean age of the patients with microalbuminuria ( 15.86 yrs ± 1.345) was higher than the mean age of the children with normoalbuminuria(14.10 ± 3.032). All cases with microalbuminuria were found to be > 12 yrs of age (after puberty) in our study. This is comparable with the previous studies which had indicated that the onset of microalbuminuria before puberty occurs only rarely and consequently screening for microalbuminuria should be recommended for children over 12 yrs of age (106-108).There are only a few reports of diabetic children who develop diabetic nephropathy in prepubertal period (109,110). On statistical analysis, there was no significant correlation between the prevalence of microalbuminuria and either the current age of the patients or age of onset of the disease, similar to the Oxford Regional Prospective study (ORPS) cohort.CONCLUSION: 1. The prevalence of microalbuminuria among type 1 diabetic patients was 12.28%. 2. 3/7 cases (42.85%) had microalbuminuria within 5 yrs of onset of diabetes. 3. The least duration of diabetes at which microalbuminuria was noted was 3 yrs. Screening for microalbuminuria in ≤ 5 yrs duration was found to be statistically significant as that of screening juvenile diabetics of more than 5 years duration. 4. Age and gender were not the significant risk factors in the development of microalbuminuria statistically. 5. 50% of patients with BMI > 95th percentile had microalbuminuria and high BMI was found to be a significant risk factor in the development of microalbuminuria. 6. Duration of diabetes was significantly associated with dyslipidemia (hypertriglyceridemia). 7. Poor glycemic control also had strong correlation with dyslipidemia (high LDL cholesterol). 8. Dyslipidemia was found to be significantly associated with microalbuminuria