Email updates

Keep up to date with the latest news and content from BMC Nephrology and BioMed Central.

Open Access Highly Accessed Research article

The relationship between obesity and diabetic nephropathy in China

Hui-Mei Chen*, Wen-Wen Shen, Yong-Chun Ge, Yi-De Zhang, Hong-Lang Xie and Zhi-Hong Liu*

Author Affiliations

Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China

For all author emails, please log on.

BMC Nephrology 2013, 14:69  doi:10.1186/1471-2369-14-69

Published: 25 March 2013

Abstract

Background

The epidemic of diabetic nephropathy (DN) has been paralleled by rapid increases in both obesity and diabetes in China. The aim of this study was to investigate the natural history of DN and the association of obesity and renal function with diabetes.

Methods

In total, 264 patients with renal biopsy-confirmed DN were examined from 2002 to 2008 and followed up to June 2008 in our institute. Among these, 129 patients were classified into a Kidney Disease Outcomes Quality Initiative (K/DOQI) stage I subgroup. Weight status, clinico-histopathological features, the development of end-stage renal disease (ESRD) and increased proteinuria were evaluated at the baseline of biopsy and during the follow up. Lean, overweight and obese phenotypes were defined as body mass index (BMI) less than 25 kg/m2, 25–28 kg/m2, and more than 28 kg/m2 over, respectively.

Results

In the patients with renal biopsy-confirmed DN, BMI was 25.5 ± 3.39 kg/m2, with 122 (46.2%), 83 (31.4%) and 59 (22.3%) having lean, overweight and obese phenotypes, respectively. Mean proteinuria was 3.09 ± 2.32 g/24 h, serum creatinine was 2.02 ± 2.02 mg/dL, and creatinine clearance rate (Ccr) was 96.0 ± 54.0 mL/min/1.73 m2. Compared with obese patients, lean patients had a lower Ccr, a higher percentage of anemia, more renal lesions and higher risk for ESRD (HR = 1.812, P = 0.048). The weight in obese patients decreased significantly after 27 months, and lean patients had a longer duration of diabetes than obese patients. Regarding patients at K/DOQI stage I, patients with DN showed similar duration of diabetes regardless of weight status. Minimal weight loss was recorded in obese patients during follow-up, and they exhibited greater glomerular hyperfiltration and higher risk for increased proteinuria (HR = 2.872, P = 0.014) than lean patients.

Conclusions

In China, obesity is common in DN patients undergoing biopsy. Initial high levels of proteinuria and subsequent weight loss are the major characteristics of the natural course of DN. Obesity contributed to increased proteinuria at an early stage, while the lean phenotype was associated with ESRD development, especially at the later stages.

Keywords:
Diabetic nephropathy; ESRD; Obesity; Proteinuria