Metabolically Healthy Obesity and Development of Chronic Kidney Disease: A Cohort Study.

BACKGROUND

The risk for chronic kidney disease (CKD) among obese persons without obesity-related metabolic abnormalities, called metabolically healthy obesity, is largely unexplored.

OBJECTIVE

To investigate the risk for incident CKD across categories of body mass index in a large cohort of metabolically healthy men and women.

DESIGN

Prospective cohort study.

SETTING

Kangbuk Samsung Health Study, Kangbuk Samsung Hospital, Seoul, South Korea.

PARTICIPANTS

62 249 metabolically healthy, young and middle-aged men and women without CKD or proteinuria at baseline.

MEASUREMENTS

Metabolic health was defined as a homeostasis model assessment of insulin resistance less than 2.5 and absence of any component of the metabolic syndrome. Underweight, normal weight, overweight, and obesity were defined as a body mass index less than 18.5 kg/m2, 18.5 to 22.9 kg/m2, 23 to 24.9 kg/m2, and 25 kg/m2 or greater, respectively. The outcome was incident CKD, defined as an estimated glomerular filtration rate less than 60 mL/min/1.73 m2.

RESULTS

During 369 088 person-years of follow-up, 906 incident CKD cases were identified. The multivariable-adjusted differences in 5-year cumulative incidence of CKD in underweight, overweight, and obese participants compared with normal-weight participants were -4.0 (95% CI, -7.8 to -0.3), 3.5 (CI, 0.9 to 6.1), and 6.7 (CI, 3.0 to 10.4) cases per 1000 persons, respectively. These associations were consistently seen in all clinically relevant subgroups.

LIMITATION

Chronic kidney disease was identified by a single measurement at each visit.

CONCLUSION

Overweight and obesity are associated with an increased incidence of CKD in metabolically healthy young and middle-aged participants. These findings show that metabolically healthy obesity is not a harmless condition and that the obese phenotype, regardless of metabolic abnormalities, can adversely affect renal function.

PRIMARY FUNDING SOURCE

None.