Trends in Albuminuria and GFR Among Adolescents in the United States, 1988-2014.

RATIONALE & OBJECTIVE: Albuminuria and low estimated glomerular filtration rate (eGFR) define chronic kidney disease in adults and youth. Different from adults, the burden of abnormal kidney markers among youth in the general United States population is largely unknown.

STUDY DESIGN: Serial cross-sectional national surveys.

SETTING & PARTICIPANTS: Adolescents aged 12 to 18 years participating in the National Health and Nutrition Examination Surveys 1988 to 2014. Surveys were grouped into three 6-year periods.

PREDICTORS: Demographic and clinical determinants of kidney markers.

OUTCOME: Prevalence and trends in persistent albuminuria, low (< 60mL/min/1.73m2 ) and reduced (< 90mL/min/1.73m2 ) eGFRs.

ANALYTICAL APPROACH: Outcomes defined as persistent albumin-creatinine ratio ≥ 30mg/g (persistent albuminuria), eGFR < 90mL/min/1.73m2 (reduced kidney function), and eGFR < 60mL/min/1.73m2 (low kidney function). Multiple imputation analysis was used to estimate missing follow-up values of albuminuria.

RESULTS: Prevalences of persistent albuminuria were 3.64% (95% CI, 1.82%-5.46%) in 1988-1994 and 3.29% (95% CI, 1.94%-4.63%) in 2009-2014 (adjusted prevalence ratio, 0.93; 95% CI, 0.53-1.62; P=0.8 for trend). Prevalences of reduced eGFR were 31.46% (95% CI, 28.42%-34.67%) and 34.58% (95% CI, 32.07%-37.18%), respectively (adjusted prevalence ratio, 1.21; 95% CI, 1.00-1.46; P < 0.001 for trend). Prevalences of low eGFR were 0.32% (95% CI, 0.12%-0.84%) in 1988-1994 and 0.91% (95% CI, 0.58%-1.42%) in 2009-2014 (adjusted prevalence ratio, 3.10; 95% CI, 1.10-9.01; P = 0.09 for trend). Prevalences of albuminuria and/or low eGFR remained at 4.0% in 1988-1994 and 2009-2014 (adjusted prevalence ratio, 1.06; 95% CI, 0.64-1.77; P = 0.8 for trend).

LIMITATIONS: Persistent albuminuria data were based on imputed values (for second assessment of albuminuria) in 91% of participants; lack of second eGFR assessment to confirm sustained reduction in kidney function.

CONCLUSIONS: Albuminuria prevalence has not changed significantly in the US adolescent population between 1988 and 2014. Prevalences of both reduced and low eGFRs were higher in the most recent study period; however, < 1% of adolescents had low eGFRs.