Relationship between body mass index and proteinuria in hypertensive nephrosclerosis: results from the African American Study of Kidney Disease and Hypertension (AASK) cohort

Am J Kidney Dis. 2010 Nov;56(5):896-906. doi: 10.1053/j.ajkd.2010.05.016.

Abstract

Background: Few studies have examined the association between obesity and markers of kidney injury in a chronic kidney disease population. We hypothesized that obesity is independently associated with proteinuria, a marker of chronic kidney disease progression.

Study design: Observational cross-sectional analysis.

Setting & participants: Post hoc analysis of baseline data for 652 participants in the African American Study of Kidney Disease (AASK).

Predictors: Obesity, determined using body mass index (BMI).

Measurements & outcomes: Urine total protein-creatinine ratio and albumin-creatinine ratio measured in 24-hour urine collections.

Results: AASK participants had a mean age of 60.2 ± 10.2 years and serum creatinine level of 2.3 ± 1.5 mg/dL; 61.3% were men. Mean BMI was 31.4 ± 7.0 kg/m(2). Approximately 70% of participants had a daily urine total protein excretion rate <300 mg/d. In linear regression analyses adjusted for sex, each 2-kg/m(2) increase in BMI was associated with a 6.7% (95% CI, 3.2-10.4) and 9.4% (95% CI, 4.9-14.1) increase in urine total protein-creatinine and urine albumin-creatinine ratios, respectively. In multivariable models adjusting for age, sex, systolic blood pressure, serum glucose level, uric acid level, and creatinine level, each 2-kg/m(2) increase in BMI was associated with a 3.5% (95% CI, 0.4-6.7) and 5.6% (95% CI, 1.5-9.9) increase in proteinuria and albuminuria, respectively. The interaction between older age and BMI was statistically significant, indicating that this relationship was driven by younger AASK participants.

Limitations: May not generalize to other populations; cross-sectional analysis precludes statements regarding causality.

Conclusions: BMI is associated independently with urine total protein and albumin excretion in African Americans with hypertensive nephrosclerosis, particularly in younger patients.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • African Americans*
  • Blood Pressure
  • Body Mass Index*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hypertension, Renal / complications
  • Hypertension, Renal / ethnology*
  • Hypertension, Renal / urine
  • Incidence
  • Male
  • Middle Aged
  • Nephrosclerosis / complications
  • Nephrosclerosis / ethnology*
  • Nephrosclerosis / urine
  • Obesity / complications
  • Obesity / ethnology*
  • Obesity / urine
  • Prognosis
  • Proteinuria / ethnology*
  • Proteinuria / etiology
  • Proteinuria / physiopathology
  • United States / epidemiology