Early-life overweight trajectory and CKD in the 1946 British birth cohort study.

BACKGROUND: Few studies have examined the impact of childhood obesity on later kidney disease, and consequently, our understanding is very limited. STUDY DESIGN: Longitudinal population-based cohort. SETTING & PARTICIPANTS: The Medical Research Council National Survey of Health and Development, a socially stratified sample of 5,362 singletons born in 1 week in March 1946 in England, Scotland, and Wales, of which 4,340 were analyzed. PREDICTOR: Early-life overweight latent classes (never, prepubertal only, pubertal onset, or always), derived from repeated measurements of body mass index between ages 2 and 20 years. OUTCOMES & MEASUREMENTS: The primary outcome was chronic kidney disease (CKD), defined as creatinine- or cystatin C-based estimated glomerular filtration rate (eGFRcr and eGFRcys, respectively) <60 mL/min/1.73 m² or urine albumin-creatinine ratio (UACR) ≥3.5 mg/mmol measured at age 60-64 years. Associations were explored through regression analysis, with adjustment for socioeconomic position, smoking, physical activity level, diabetes, hypertension, and overweight at ages 36 and 53 years. RESULTS: 2.3% of study participants had eGFRcr <60 mL/min/1.73 m², 1.7% had eGFRcys