Prevalence & Risk Factors of Nephropathy in Type 2
Diabetic Patients

Vimalkumar V K; C.R. An; Moses; Padmanaban S.

Prevalence & Risk Factors of Nephropathy in Type 2 Diabetic Patients

Vimalkumar V K , C.R. Anand Moses, Padmanaban S.

Vimalkumar V K^*, C.R. Anand Moses, Padmanaban S.

Kilpauk Medical College, Chennai, India

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Abstract

Background: 31.7 million people in India are suffering from diabetes. Diabetic nephropathy (Kimmelstiel-Wilson syndrome) is the leading cause of end-stage renal disease (ESRD) worldwide and a leading cause of DM-related morbidity and mortality. It is estimated that 79.4 million diabetic patients will be in India by 2030. So a study was done on the prevalence rate of diabetic nephropathy (DN) and its associated risk factors.

Aims and Objectives: This study is a small cross sectional study conducted in a tertiary hospital (Dr. Ambedkar institute of diabetes, Kilpauk medical college hospital, Chennai.). The objective is to analyze the prevalence of DN and to determine the factors leading to DN in type 2 diabetic patients (mainly containing urban Asian Indian population)

Materials and Methods: 200 Type 2 diabetic patients were randomly selected. All the patients were interviewed with a questionnaire. A detailed history including risk factors like age ,sex , socio economic status, duration of diabetes , smoking , alcohol , family history of DM and kidney disease, Ischemic heart disease(IHD), Oral Hypoglycemic Drugs(OHA) , Insulin was taken followed by measurement of blood pressure, BMI assessment, urine analysis for albuminuria and microalbuminuria using dipsticks, lipid profile, GFR estimation, retinopathy screening. Statistical analysis was done by SPSS software. Univariate analysis, Chi-square and Binary Logistic Regression Model was used.

Results: In this study prevalence rate of overt nephropathy is 2.5% and microalbuminuria is 13%, Using Binary logistic regression analysis, Woman gender, Duration of diabetes, family history of kidney disease, Hypertension, BMI, GFR, retinopathy were found to be significantly associated with overt DN. There was no increased risk among IHD patients, smokers, alcoholics and no significant relationship with treatment history.

Limitations: This is a hospital based cross sectional study. Population based Case control studies should be conducted for assessment of multiple risk factors. This triggers the need for studies with higher sample size to assess various risk factors and mass screening programs.

Conclusion: According to study, as the duration of diabetes increases, the incidence of nephropathy also increases and is statistically significant. Hence all diabetic patients, especially those with increased duration should be screened for nephropathy and made aware of the complications. Since nephropathy is a forerunner for end stage renal disease, preventive measures can help in preventing renal failure.

Keywords

Diabetic nephropathy, risk factors, diabetes

Introduction

Diabetes mellitus (DM) refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. Several distinct types of DM exist and are caused by a complex interaction of genetics and environmental factors. [1] 50,768,300 People in India suffer from diabetes according to diabetes atlas of IDF (international diabetes federation. It is estimated that 79.4 million diabetic patients will be in India by 2030, 439 million adults in world (corresponding to 7.8% of the world's adult population) by 2030. [2] The chronic complications of DM affect many organ systems and are responsible for the majority of morbidity and mortality associated with the disease.[3] Chronic complications can be divided into vascular and nonvascular complications. The vascular complications of DM are further subdivided into microvascular (retinopathy, neuropathy, and nephropathy) and macrovascular complications [coronary artery disease (CAD), peripheral arterial disease (PAD), cerebrovascular disease] Diabetic nephropathy (Kimmelstiel-Wilson syndrome) is the leading cause of end-stage renal disease (ESRD) worldwide and a leading cause of DM-related morbidity and mortality. Both microalbuminuria and macroalbuminuria in individuals with DM are associated with increased risk of cardiovascular disease.[7] Individuals with diabetic nephropathy commonly have diabetic retinopathy.[4] So a study was done on the prevalence rate of diabetic nephropathy (DN) and its associated risk factors.

Aims and Objectives

This study is a small cross sectional study conducted in a tertiary hospital (Dr. Ambedkar institute of diabetes, Kilpauk medical college hospital, Chennai.). The objective is to analyze the prevalence of DN and to determine the factors leading to DN in type 2 diabetic patients (mainly containing urban Asian Indian population)

Materials and Methods

Age, gender, family history (of diabetes, of kidney disease), smoking h/o were obtained from the questionnaire. Ethical committee approval was obtained from Institutional ethical committee.

Height: Height was measured by a tape measure fixed to wall and a movable headboard. Subjects were asked to remove the foot wears, stand upright with feet flat, arms by the side, shoulders level, with head, shoulders, buttocks, and heels touching the wall and eyes directed forward

Weight: Weight was calculated by standard weighing scale in kg. The person stands with minimal movement with hands by their side. Shoes and excess clothing were removed.

BMI: The body mass index was calculated using the following formula:Weight (kg)/height (m2).

Measuring BP

Prior to the BP measurement, the patient was seated in a quiet room with selected arm free of constricted clothing so that the cuff can be wrapped around the upper arm without impediment. Blood pressure is recorded for systolic and diastolic BP to the nearest 2 mmHg using mercury sphygmomanometer. The same procedure is repeated with 30 seconds interval and the mean of the two was taken as the final blood pressure reading.

A blood pressure more than 140/90 mm hg is taken as hypertension.

Blood Sample

The blood sample was used to measure serum triglycerides, ldl, hdl and creatinine. Gfr was calculated from the serum creatinine using the MDRD formula. GFR (mL/min/1.73 m2) = 186 x (Pcr)-1.154 x (age)-0.203 x (0.742 if female) x (1.210 if African American)

Urine Sample

Urine sample was used to find microalbuminuria and macroalbuminuria using dipstick methods.

Microalbuminuria is defined as 30–300 mg/d in a 24-h collection or 30–300 mg/mg creatinine in a spot collection

Retinopathy

Retinopathy was diagnosed by optic fundoscopy

Statistical Tool

SPSS software was used for analysis and binary logistic regression model was performed for the risk factors with respect to diabetic nephropathy.

A p value of <0.05 was considered significant.

Observation and Results

In this study prevalence rate of overt nephropathy is 2.5% and microalbuminuria is 13%, Using Binary logistic regression analysis, woman gender, Duration of diabetes, family history of kidney disease, Hypertension, high bmi, low Gfr, retinopathy were found to be significantly associated with DN.

Discussion

200 patients for the study were selected based on the following inclusion criteria

• All known type 2 diabetic patients attending the Diabetology clinic (Dr. Ambedkar institute of diabetes, Kilpauk medical college hospital, Chennai.).

• Patients under regular treatment.

The following variables were studied in detail with respect to nephropathy (microalbuminuria).

A. Age, duration of diabetes.

B. Gender

C. Family history of diabetes and kidney disease

D. Smoking

E. Bmi

F. Hypertension

G. Triglyceride, ldl, hdl

H. Gfr

I. Retinopathy

The details of the studied variables (including tables and figures) are provided at the end of the article.

Binary Logistic Regression Model

Dependent Variable: nephropathy

Risk Factors Tested: age, duration of diabetes, gender, family history, smoking, BMI, hypertension, triglyceride, LDL, HDL, GFR, and retinopathy.

Risk Factors Significant: woman gender, duration of diabetes, family history of kidney disease, hypertension, BMI, GFR, retinopathy.

Conclusion

According to study, as the duration of diabetes increases, the incidence of nephropathy also increases and is statistically significant. Hence all diabetic patients, especially those with increased duration should be screened for nephropathy and made aware of the complications. Since nephropathy is a forerunner for end stage renal disease, preventive measures can help in preventing renal failure. Microalbuminuria may be present even before the diagnosis in a latent period, which needs to be identified as it is a potentially reversible form of kidney injury. So screening measures should be made effective.

Limitations

This is a hospital based cross sectional study. Population based Case control studies should be conducted for assessment of multiple risk factors. This triggers the need for studies with higher sample size to assess various risk factors and mass screening programs. Other causes of proteinuria such as prostate disease, infection, CCF has to be ruled out.

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