Table 5.
Characteristics of NHANES 2009–2012 participants by adequacy of the collected spot urine sample following the WHO guidelines based on urine creatinine concentrations.
| Over-diluted urine specimen (Urine creatinine <0.3 g/l) N (%) =756 (8.1) |
Adequate urine specimen (urine creatinine ≥0.3 g/l &≤3 g/l) N (%) =9601 (88.8) |
Over-condensed urine specimen (Urine creatinine > 3 g/l) N (%) =412 (3.1) |
p-value | |
|---|---|---|---|---|
| Percentage (%) in Category | ||||
| Male (%) | 26.1 | 51.5 | 69.2 | <0.01 |
| Race (%) | <0.01 | |||
| Non-Hispanic white | 76.7 | 67.4 | 50.3 | |
| Non-Hispanic black | 3.3 | 10.7 | 34.8 | |
| Mexican American | 4.3 | 9.0 | 5.8 | |
| Others | 15.7 | 13.0 | 9.1 | |
| Hypertension (%) | 66.5 | 62.0 | 68.3 | 0.05 |
| Diabetes (%) | 14.3 | 18.8 | 12.6 | 0.08 |
| Chronic kidney disease (%) | 4.2 | 6.3 | 4.2 | 0.01 |
| Diuretics usage (%) | 9.4 (N=405) | 11.1 (N=5193) | 4.2 (N=212) | 0.01 |
| Median (Interquartile range) | ||||
|
| ||||
| Age (year) | 48 (35–59) | 45 (30–59) | 31 (23–46) | <0.01 |
| Body mass index (kg/m2) | 25.3 (22.3–28.9) | 27.5 (23.9–32.0) | 28.7 (24.6–33.1) | <0.01 |
| eGFR (ml/min/1.73m2) | 98.8 (86.5–111.4) | 97.3 (82.3–112.0) | 100.4 (86.6–117.3) | <0.01 |
| Blood glucose (mg/dL) | 96 (89–103) (N=278) | 98 (92–107) (N=4809) | 98 (90–104) (N=171) | 0.004 |
| Fasting time (min) | 721 (637–781) (N=278) | 701 (632–790) (N=4815) | 687 (620–784) (N=171) | 0.83 |
| Urine osmolality (mOsm/kg) | 176 (132–227) | 666 (453–840) | 990 (858–1076) | <0.01 |
| Blood osmolality (mmol/kg) | 276 (273–279) | 278 (275–281) | 278 (275–281) | <0.01 |
| Total protein intake (gm/day) | 73.4 (53.1–94.8) (N=384) | 77.6 (55.2–104.1) (N=5023) | 73.7 (49.0–104.5) (N=202) | 0.11 |
| Total water intake (gm/day) | 948 (296.3–1866.4) (N=384) | 681.4 (177.8–1481.3) (N=5023) | 414.8 (0–1184) (N=202) | <0.01 |
*
Median (interquartile range) and frequencies (percentages) are presented for continuous and categorical variables, respectively. P-values were derived from ANOVA and chi-square test for continuous and categorical variables, respectively.
Abbreviation: eGFR, estimated glomerular filtration rate
#
The sample sizes for diuretic use and nutrient and water intake were smaller as the information was only available for participants in NAHNES 2009–2010 at the time of analysis.