Changes in weight during the first year after kidney transplantation

Obesity frequently occurs following kidney transplantation and is of concern because of the associated risk for cardiovascular complications.

To examine weight gain over the first year after kidney transplantation to determine associations with gender, ethnicity, and cardiovascular risk factors.

A retrospective analysis was completed on patients who had received transplants between January 1998 and January 2002 and who had matching baseline and 1-year follow-up data and a functional graft.

The sample consisted of 171 recipients (33% women, 58% African Americans, and 39% whites) with a mean age of 44 +/- 12.2 years.

Outcome measures included fasting blood sugar, triglycerides, creatinine levels, and body mass index categorized as normal, overweight, or obese.

The total group showed a significant increase in mean weight (6.2 +/- 10.7 kg) and body mass index (2.1 +/- 3.8). Although equivalent at baseline, by 1 year after transplantation there were significantly more obese than normal-weight recipients, regardless of gender or ethnicity, with African Americans increasing more than whites and women more than men. At baseline, those characterized as obese versus normal weight were older (47 vs. 41 years; P < .05), with a higher fasting blood sugar. At 1 year, differences in age and fasting blood sugar disappeared; however, the obese group had higher triglycerides (235 vs. 165, P = .01).

Weight gain after transplantation was not explained by demographic and clinical factors. We speculate additional variables such as genetic factors influence weight gain and warrant study.