Background:
Dietary protein intake has been associated with renal disease progression in patients with chronic kidney disease (CKD). Little is known about the renal impact of protein intake in persons with hypertension or diabetes who are at high risk for CKD.
Objectives:
This study aims to evaluate protein intake in relation to CKD in a representative sample of US adults, stratified by hypertension and diabetes.
Methods:
A cross-sectional study was conducted using data from the US NHANES 2003-2008. Subjects were excluded if they were pregnant, with known weak kidney, or following on special diet. There were 9,284 eligible participants age 20-80 with data from two 24-hour dietary recall questionnaires. Protein intake was adjusted for energy intake and categorized into four evenly spaced groups. CKD was defined as an estimated glomerular filtration rate <60mL/min/1.73m
2
. Logistical regression model was used to estimate the prevalence odds ratio (POR). Analyses were further stratified by hypertension and diabetes.
Results:
The median protein intake was 77 g/day (interquartile range, 66 to 89 g/day) in the study population, and was 59, 72, 83, and 100 g/day for the lowest to the highest quarter of protein intake, respectively. The prevalence of CKD was 4%. For a 25-g increase in protein intake, the POR was 1.18 (95% CI: 0.93 to 1.50), adjusting for age, sex, race, income adequacy, education level, energy intake, physical activity, cardiovascular disease, diabetes, and hypertension. The adjusted POR comparing the highest and the lowest quarter of protein intake was 1.12 (95%CI: 0.73 to 1.72). The stratified analysis showed the highest quarter is associated with CKD among persons with both hypertension and diabetes (
Table
). No association was found in persons with hypertension only, diabetes only, or neither.
Conclusion:
We observed a positive association between protein intake and CKD among American adults with both hypertension and diabetes. This finding adds to the concern of dietary protein intake in persons at high-risk for CKD.
Table.
Adjusted POR of CKD comparing the highest and the lowest quarter of protein intake.
Disease Status
Hypertension
-
+
Diabetes
-
1.05 (0.45 - 2.45)
0.80 (0.44 - 1.47)
+
4.63 (0.33 - 65.70)
3.04 (1.13 - 8.19)
Vegetarian Compared with Meat Dietary Protein Source and Phosphorus Homeostasis in Chronic Kidney Disease
