Clinical trial NCT02435017: Dietary Phosphate and Serum Phosphorus
Official title: Nutrition Risk Screening in Chronic Kidney Disease (CKD) From the National Health and Nutrition Examination Survey
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Phosphorus Metabolism Disorders
Keywords: kidney disease
recommended dietary allowances
nutrition assessment
food
dietary proteins
Vitamin D
dietary fats
ethnology
Continental Population Groups
Phosphorus, dietary
Phosphorus/analysis
Lead sponsor: The Methodist Hospital Research Institute
Sponsor class: OTHER
Collaborators: name: The Methodist Hospital Research Institute
First posted: 2015-05-06
Enrollment: 7895
Sex: ALL
Minimum age (years): 20
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: Participants in the continuous NHANES program from 2003-2006 who met the inclusion/exclusion criteria were included in the analysis. NHANES samples the general US population to determine prevalence of major diseases and health risks by combining physical examination with laboratory studies and questionnaires in a standardized environment using trained personnel. Participants are selected through a complex, multistage, probability sampling approach.

Brief summary: Overall study design is to review National Health and Nutrition Examination Survey (NHANES) data 1999-2008 for nutrition risk according to kidney function. Substudies will be performed to review the association of nutrients and overall dietary intake compared to biomarkers available in NHANES during this period.

Detailed description: Data from NHANES 2003-2006 were used to evaluate the relationship between estimated dietary phosphorus intake and the measured serum phosphorus. The following variables were used:

1. Demographics: Age, sex, race/ethnicity
2. Dietary variables: Foods, food groups (as reported by the United States Department of Agriculture (USDA) method, further standardized to the Academy of Nutrition and Dietetics method for portion size and then divided into groups having inorganic phosphate additives or no inorganic phosphate additives), food weight (g), phosphorus (mg), dietary supplements
3. Socioeconomic variables: education, family income
4. Laboratory variables: serum creatinine, phosphorus; urine albumin, creatinine
5. Clinical assessments: hypertension (proportion having blood pressure ≥140 millimeters of mercury (mmHg) diastolic or ≥90 mmHg systolic or taking antihypertensive medications); hyperglycemia (proportion having serum glucose \>126 mg/dL or taking medications for diabetes); kidney function based on Chronic Kidney Disease Epidemiology Collaboration (2009) equation, evaluated in 15 milliliters/min/1.73m2 increments from \<15 to \>105; anthropometrics (BMI, kg/m2; obesity class I, II, III)

Eligibility criteria: Inclusion Criteria:

* Serum creatinine

Exclusion Criteria:

* Pregnancy
* No dietary intake interview
* Dietary intake interview not valid
* Answered the question "Have you had dialysis in the past year?" as "Yes"

Primary outcomes:
measure: Serum phosphorus concentration
timeFrame: approximately 24 hours
Secondary outcomes:
measure: Kidney function level
timeFrame: Baseline
Other outcomes:
Locations:
Study officials:
affiliation: Director, Clinical Trials; Dept of Surgery
name: Linda W Moore, MS
role: PRINCIPAL_INVESTIGATOR
References:
citation: Moore LW, Byham-Gray LD, Scott Parrott J, Rigassio-Radler D, Mandayam S, Jones SL, Mitch WE, Osama Gaber A. The mean dietary protein intake at different stages of chronic kidney disease is higher than current guidelines. Kidney Int. 2013 Apr;83(4):724-32. doi: 10.1038/ki.2012.420. Epub 2013 Jan 9.
citation: Moore LW, Nolte JV, Gaber AO, Suki WN. Association of dietary phosphate and serum phosphorus concentration by levels of kidney function. Am J Clin Nutr. 2015 Aug;102(2):444-53. doi: 10.3945/ajcn.114.102715. Epub 2015 Jun 3.