Obesity paradox and chronic kidney disease

In general population, obesity is associated with increased risk of adverse outcomes. However, the studies carried out in the past years have offered a new insight into obesity when associated with chronic disease states such as chronic heart disease, heart failure, chronic kidney disease, end-stage renal disease, etc. Studies of patients with these chronic diseases suggest that the outcomes of overweight and obese patients may be paradoxically better than in lean patients. The aim of our study was to identify how BMI can influence the renal and cardiac functions.

We carried out a retrospective study on 93 patients (51 males and 42 females; mean age 60.83 +/- 12.32 years) with chronic kidney disease in different stages of chronic renal failure according to K/DOQI.

We found significantly higher GFR and lower creatinine levels in obese patients when compared to normal subjects (p = 0.0009, and p = 0.05, respectively). When comparing the group of obese patients (BMI >30) with normal subjects, we found significantly higher values of EF (p = 0.05) and S vel (global radial myocardial velocity of the left ventricle in systole; p = 0.04) in obese patients. There were no significant differences between these three groups of patients in other parameters such as B-type of natriuretic peptide, C-reactive protein, and fibrinogen (p = 0.2, p = 0.4, and 0.9, respectively).

In our group of 93 patients with chronic kidney disease in different stages of chronic renal failure, we have proved no adverse effect of obesity on cardiac or renal function (Tab. 4, Fig. 3, Ref. 27).