A recent study has linked weight fluctuations--or body mass index variability--to higher risks of cardiovascular-related problems and early death in adults with chronic kidney disease (CKD). The findings of the study appear in the journal JASN. Body mass index variability is associated with higher risks of developing heart conditions in the general population.

Because cardiovascular disease is the leading cause of death in individuals with CKD, a team led by Dong Ki Kim, MD, PhD, Sehoon Park, MD, and Kyungdo Han, PhD examined whether BMI variability may affect the prognosis of patients with kidney dysfunction. The study included 84,636 patients with CKD who were listed in a national health screening database in South Korea. During a median follow-up of 4 years, 6 per cent of individuals died, 4 per cent needed kidney replacement therapy such as dialysis, 2 per cent suffered a heart attack, and three per cent suffered a stroke.

Compared with individuals with the lowest body mass index variability, those with the highest body mass index variability faced a 66 per cent higher risk of dying, a 20 per cent higher risk of needing kidney replacement therapy, a 19 per cent higher risk of experiencing a heart attack, and a 19 per cent higher risk of experiencing a stroke. "This study showed that people who had kidney function impairment with recent fluctuating body mass index had a higher risk of cardiovascular disease or death, regardless of their current body mass index," said Dr Kim, of Seoul National University Hospital.

"This result suggests that people with kidney function impairment should pay attention to their fluctuating weight status, and those with fluctuating weight may benefit from receiving appropriate screening and risk factor management to prevent cardiovascular disease or progression of their kidney dysfunction," added Dr Kim. The results were similar in the subgroups divided according to positive/negative trends in BMI during the exposure assessment period.

In addition, variabilities in certain metabolic syndrome components were also significantly associated with the prognosis of predialysis CKD patients. Furthermore, those with a higher number of metabolic syndrome components with high variability had a worse prognosis.