Relationship Between Body Mass Index and Proteinuria in Hypertensive Nephrosclerosis: Results From the African American Study of Kidney Disease and Hypertension (AASK) Cohort
The University of Texas Southwestern Medical Center Dallas, Dallas, TX 75390-8856, USA. American Journal of Kidney Diseases
(Impact Factor: 5.9).
11/2010; 56(5):896-906. DOI: 10.1053/j.ajkd.2010.05.016
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.
Observational cross-sectional analysis.
Post hoc analysis of baseline data for 652 participants in the African American Study of Kidney Disease (AASK).
Obesity, determined using body mass index (BMI).
Urine total protein-creatinine ratio and albumin-creatinine ratio measured in 24-hour urine collections.
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.
May not generalize to other populations; cross-sectional analysis precludes statements regarding causality.
BMI is associated independently with urine total protein and albumin excretion in African Americans with hypertensive nephrosclerosis, particularly in younger patients.
Available from: Melvin Hayden
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ABSTRACT: Obesity has reached epidemic proportions with far-reaching health care and economic implications. Overnutrition, characterized by excess intake of carbohydrates and fats, has been associated with end-organ damage in several tissues, including the heart and the kidney. Furthermore, overnutrition is one of the most important modifiable and preventable causes of morbidity and mortality associated with cardiovascular and kidney diseases. Insulin resistance and compensatory hyperinsulinemia as well as associated mechanisms, including enhanced renin-angiotensin-aldosterone system activity, inflammation, and oxidative stress, have been implicated in obesity-related cardiorenal injury. In this review, the effect of overnutrition on heart and kidney disease is assessed in a rodent model of overnutrition and obesity, the Zucker obese rat.
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ABSTRACT: Albuminuria is associated with atherothrombotic events and all-cause mortality in patients with and without diabetes. However, it is not known whether albuminuria is associated with atherosclerosis per se in the same manner. The present study included 914 consecutive white patients who had been referred for coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD). Albuminuria was defined as a urinary albumin/creatinine ratio ≥ 30 μg/mg. Microalbuminuria was defined as 30 to 300 μg albumin/mg creatinine, and macroalbuminuria as a urinary albumin/creatinine ratio of ≥ 300 μg/mg. The prevalence of stenoses of ≥ 50% was significantly greater in patients with albuminuria than in those with normoalbuminuria (66% vs 51%; p <0.001). Logistic regression analysis, adjusted for age, gender, diabetes, smoking, hypertension, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, C-reactive protein, body mass index, estimated glomerular filtration rate, and the use of angiotensin-converting enzyme inhibitors/angiotensin II antagonists, aspirin, and statins, confirmed that albuminuria was significantly associated with stenoses ≥ 50% (standardized adjusted odds ratio [OR] 1.68, 95% confidence interval [CI] 1.15 to 2.44; p = 0.007). The adjusted OR was 1.54 (95% CI 1.03 to 2.30; p = 0.034) for microalbuminuria and 2.55 (95% CI 1.14 to 5.72; p = 0.023) for macroalbuminuria. This association was significant in the subgroup of patients with type 2 diabetes (OR 1.66, 95% CI 1.01 to 2.74; p = 0.045) and in those without diabetes (OR 1.42, 95% CI 1.05 to 1.92; p = 0.023). An interaction term urinary albumin/creatinine ratio*diabetes was not significant (p = 0.579). In conclusion, micro- and macroalbuminuria were strongly associated with angiographically determined coronary atherosclerosis in both patients with and those without type 2 diabetes mellitus, independent of conventional cardiovascular risk factors and the estimated glomerular filtration rate.
Available from: Garabed Eknoyan
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ABSTRACT: Obesity is associated with the early onset of glomerulomegaly, hemodynamic changes of a hyperfiltering kidney, and increased albuminuria, which are potentially reversible with weight loss. However, pathologic lesions of focal segmental glomerulosclerosis develop in experimental models of sustained obesity, and are observed in morbidly obese humans presenting with massive proteinuria. In addition, several observational, cross sectional and longitudinal studies document that obesity is as an independent risk factor for the onset, aggravated course, and poor outcomes of chronic kidney disease, even after adjustment for confounding co-morbidities including metabolic syndrome, diabetes and hypertension, the major causes of chronic kidney disease. Early dietary intervention to reduce weight, and where necessary bariatric surgery, should be considered in the management of overweight and obese chronic kidney disease (CKD) patients.
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