Kidneys are exquisitely sensitive to many risk factors that can also accelerate atherosclerosis and heart disease. Thus, high blood pressure and diabetes are well-established risk factors for chronic kidney disease (CKD).
Because both hypertension and diabetes are in turn linked to obesity, the question is: does obesity increase the risk for CKD?
This questions was now addressed by Meredith Foster and colleagues from the National Heart, Lung, and Blood Institute, Framingham, MA, USA, who studied the relationship between Stage 3 CKD (= moderately reduced kidney function) and BMI in the Framingham Offspring participants (n = 2,676; 52% women; mean age, 43 years) free of stage 3 CKD at baseline who participated in examination cycles 2 (1978-1981) and 7 (1998-2001). (Am J Kidney Dis)
While there was no increased risk of kindey disease in overweight participants, obese individuals had a 68% increased odds of developing Stage 3 CKD (estimated glomerular filtration rate < 59 mL/min/1.73 m(2) for women and < 64 mL/min/1.73 m(2) for men).
However, this relationship became non-significant when data was adjusted for diabetes, systolic blood pressure, hypertension treatment, current smoking status, and high-density lipoprotein cholesterol level.
The authors rightly conclude that the link between obesity and CKD is largely explained by the effect of obesity on other cardiovascular risk factors like hypertension or diabetes.
Clearly, if your excess weight is raising your blood pressure and/or making you diabetic, you may need to start worrying about your kidneys.