Background
Methods
Study participants
Study centers
Inclusion and exclusion criteria
Sampling strategy
Study measurements
Ascertainment of 24 h-urine volume
Statistical analysis
Results
Baseline characteristics according to sex
Characteristic (n =1300) | Women (n = 661) | Men (n = 639) | P value* |
---|---|---|---|
Age, years | 48 (33 – 62) | 51 (34 – 64) | 0.05 |
Fluid intake [Liter/24 h] | 1.5 (1.5 – 2.0) | 1.5 (1.2 – 2.0) | 0.86 |
Urine volume [Liter/24 h] | 2.0 (1.4 – 2.6) | 1.8 (1.2 – 2.4) | 0.002 |
Urinary creatinine excretion [mg/kg/24 h] | 16.9 (14.0 – 19.8) | 21.5 (18.4 – 24.5) | <.0001 |
Urinary sodium excretion [mmol/24 h] | 128 (95 – 170) | 176 (131 – 224) | <.0001 |
Serum creatinine [μmol/L] | 70 (63 – 77) | 87 (80 – 96) | <.0001 |
Creatinine clearance [ml/min] | 96 (79 – 114) | 122 (101 – 142) | <.0001 |
eGFR (CKD-EPI) [ml/min/1.73 m2] | 89 (76 – 104) | 90 (77 – 103) | 0.99 |
Body mass index [kg/m2] | 24 (21 – 27) | 26 (23 – 29) | <.0001 |
Hypertension | 128 (19%) | 226 (35%) | <.0001 |
Oral anti-diabetic medication | 14 (2%) | 30 (5%) | 0.009 |
Education
| <.0001 | ||
Primary level | 74 (11%) | 61 (10%) | |
Secondary level | 315 (48%) | 246 (39%) | |
Tertiary level | 234 (35%) | 302 (47%) | |
Other | 34 (5%) | 29 (5%) | |
Smoking
| 0.0008 | ||
Current Smokers | 106 (16%) | 110 (17%) | |
Past Smokers | 164 (25%) | 213 (33%) | |
Never Smokers | 387 (58%) | 306 (48%) | |
Cups of coffee per day
| 0.46 | ||
0 | 55 (9%) | 42 (7%) | |
1-3 | 443 (67%) | 415 (65%) | |
≥4 | 160 (24%) | 179 (28%) | |
Alcohol consumption
| <.0001 | ||
Never | 137 (20%) | 53 (8%) | |
1 – 2 times/week | 402 (61%) | 309 (48%) | |
> two days/week to daily | 99 (15%) | 206 (32%) | |
twice daily or more | 12 (2%) | 66 (10%) | |
Vegetables and vegetables juices
| <.0001 | ||
< once a day | 101 (15%) | 183 (29%) | |
1 – 2 portions daily | 368 (56%) | 350 (55%) | |
≥3 portions daily | 187 (28%) | 100 (16%) | |
Fruits and fruit juices
| <.0001 | ||
< once a day | 126 (19%) | 223 (35%) | |
1 – 2 portions daily | 343 (52%) | 310 (49% | |
>3 portions daily | 189 (29%) | 98 (15%) | |
Meat or cold cut
| <.0001 | ||
once or < once weekly | 142 (21%) | 54 (8%) | |
2 – 4 days weekly | 384 (58%) | 318 (50%) | |
>5 days weekly | 134 (20%) | 265 (41%) |
Baseline characteristics according to low versus high 24-hour urine volume
Characteristic (n =650) | Low 24UV (n =325) | High 24UV (n =325) | P value* |
---|---|---|---|
Urine volume [L/24 h] | 1.0 (0.9 – 1.2) | 2.9 (2.7 – 3.5) | --- |
Age, years | 48 (30 – 63) | 47 (35 – 60) | 0.97 |
Fluid intake [L/24 h] | 1.5 (1.0 – 1.5) | 2.0 (1.5 – 2.5) | <.0001 |
Urinary creatinine excretion [mg/kg/24 h] | 18.5 (15.1 – 22.7) | 19.3 (16.1 – 22.5) | 0.14 |
Urinary sodium excretion [mmol/24 h] | 120 (94 – 165) | 171 (130 – 214) | <.0001 |
Serum creatinine [μmol/L] | 80 (70 – 91) | 75 (66 – 86) | 0.0002 |
Creatinine clearance [ml/min] | 121 (100 – 142) | 109 (90 – 132) | 0.0044 |
eGFR (CKD-EPI) [ml/min/1.73 m2] | 91 (75 – 107) | 93 (81 – 105) | 0.21 |
Body mass index [kg/m2] | 24 (22 – 28) | 24 (22 – 27) | 0.72 |
Hypertension | 82 (25%) | 72 (22%) | 0.04 |
Oral anti-diabetic medication | 13 (4%) | 5 (2%) | 0.11 |
History of nephrolithiasis | 32 (9.7%) | 27 (8.2%) | 0.79 |
Education
| 0.01 | ||
Primary level | 44 (14%) | 28 (8%) | |
Secondary level | 152 (47%) | 138 (42%) | |
Tertiary level | 110 (34%) | 147 (45%) | |
Other | 17 (5%) | 12 (4%) | |
Smoking
| 0.09 | ||
Current Smokers | 64 (20%) | 49 (15%) | |
Past Smokers | 78 (24%) | 99 (30%) | |
Never Smokers | 178 (55%) | 176 (53%) | |
Cups of coffee per day
| 0.19 | ||
0 | 27 (8%) | 17 (5%) | |
1-3 | 224 (69%) | 207 (63%) | |
≥4 | 72 (22%) | 100 (31%) | |
Alcohol consumption
| 0.10 | ||
Never | 53 (16%) | 39 (12%) | |
1 – 2 times/week | 172 (53%) | 190 (58%) | |
> two days/week to daily | 71 (22%) | 79 (24%) | |
twice daily or more | 23 (7%) | 17 (5%) | |
Vegetables and vegetables juices
| <.0001 | ||
< once a day | 104 (32%) | 53 (16%) | |
1 – 2 portions daily | 164 (50%) | 176 (54%) | |
≥3 portions daily | 55 (17%) | 92 (28%) | |
Fruits and fruit juices
| 0.04 | ||
< once a day | 110 (34%) | 68 (21%) | |
1 – 2 portions daily | 157 (48% | 173 (53%) | |
>3 portions daily | 55 (17%) | 82 (25%) | |
Meat or cold cut
| 0.08 | ||
once or < once weekly | 49 (15%) | 67 (21%) | |
2 – 4 days weekly | 187 (58%) | 154 (47%) | |
>5 days weekly | 89 (27%) | 103 (32%) |
Factors associated with 24-hour urinary volume
N = 1254 | Without Fluid Intake in the model | With Fluid Intake in the model | ||
---|---|---|---|---|
Beta (95% CI) | P value | Beta (95% CI) | P value | |
Fluid intake [Liter/day] | --- | --- | 604.4 (539.3, 670.0) | <.0001 |
Age [years] | 2.4 (−1.1, 5.9) | 0.18 | 6.6 (3.4, 9.7) | <.0001 |
Female sex | 230.8 (111.5, 350.0) | 0.0002 | 280.4 (174.4, 386.4) | <.0001 |
Body mass index [kg/m2] | −30.6 (−46.1, -15.4) | 0.0001 | −31.7 (−45.4, -18.0) | <.0001 |
German-speaking cantons | 306.6 (201.8, 411.4) | <.0001 | 124.0 (28.9, 219.0) | 0.011 |
Diabetes medication | −18.8 (−280.7, 243.4) | 0.89 | 34.8 (−197.8, 267.4) | 0.77 |
Hypertension | −67.1 (−193.6, 59.4) | 0.30 | −51.4 (−163.6, 60.9) | 0.37 |
Urinary creatinine excretion [mg/kg/24 h] | −24.9 (−42.7, -7.2) | 0.0059 | −16.0 (−31.8, -0.2) | 0.047 |
Urinary sodium excretion [mmol/24 h] | 4.5 (3.7, 5.4) | <.0001 | 4.2 (3.4, 4.9) | <.0001 |
Creatinine Clearance [ml/min] | 3.4 (0.9, 5.9) | 0.0083 | 2.4 (0.2, 4.6) | 0.036 |
Current Smoking | −215.5 (−349.2, -81.0) | 0.0017 | −145.6 (−265.2, -26.1) | 0.017 |
Past Smoking | 7.8 (−100.7, 116.3) | 0.89 | 5.9 (−90.4, 102.1) | 0.91 |
Season
†
| ||||
Spring | 100.7 (−34.3, 235.8) | 0.14 | 40.1 (−79.9, 160.1) | 0.51 |
Summer | −20.4 (−149.5, 108.7) | 0.76 | −40.1 (−154.7, 74.4) | 0.49 |
Winter | −93.3 (−240.0, 53.4) | 0.21 | −82.8 (−213.0, 47.4) | 0.21 |
Education
†
| ||||
Secondary level | −37.7 (−199.8, 124.3) | 0.65 | −5.1 (−149.0, 138.7) | 0.94 |
Tertiary level | 17.6 (−146.7, 181.9) | 0.83 | 35.0 (−110.8, 180.8) | 0.64 |
Other | −23.8 (−282.3, 234.7) | 0.86 | −24.5 (−253.9, 204.9) | 0.84 |
Cups of coffee per day
†
| ||||
1-3 | 120.4 (−57.1, 298.0) | 0.18 | 112.0 (−45.6, 269.4) | 0.16 |
≥4 | 226.2 (31.3, 421.1) | 0.023 | 158.7 (−14.3, 331.8) | 0.07 |
Alcohol consumption
†
| ||||
1 – 2 times/week | 181.9 (43.5, 320.2) | 0.010 | 173.7 (51.0, 296.5) | 0.006 |
> two days/week to daily | 189.3 (27.1, 351.4) | 0.022 | 188.1 (44.2, 332.0) | 0.010 |
twice daily or more | 286.5 (51.0, 522.0) | 0.017 | 338.5 (129.5, 547.6) | 0.002 |
Vegetables
†
| ||||
1 – 2 portions daily | 109.9 (−10.4, 230.1) | 0.073 | 89.7 (−17.0, 196.4) | 0.09 |
≥3 portions daily | 242.1 (93.1, 391.2) | 0.002 | 156.1 (23.5, 288.8) | 0.02 |
Fruits and fruit juices
†
| ||||
1 – 2 portions daily | 57.6 (−56.6, 171.8) | 0.32 | 6.6 (−94.9, 108.0) | 0.90 |
>3 portions daily | 133.2 (−7.9, 274.2) | 0.06 | 52.0 (−73.4, 177.4) | 0.42 |
Meat or cold cut
†
| ||||
2 – 4 days weekly | −184.5 (−323.7, -45.3) | 0.009 | −163.3 (−286.8, -39.8) | 0.01 |
>5 days weekly | −193.3 (−349.1, -37.5) | 0.015 | −221.9 (−360.1, -83.6) | 0.002 |
Association of linguistic regions with 24-hour urine volume
Beta | 95% Confidence Limits | P value | |
---|---|---|---|
Crude model (n = 1300) | 376.8 | (280.4, 473.2) | <.0001 |
Model 1*
| 339.9 | (232.8, 447.0) | <.0001 |
Model 2†
| 306.6 | (201.8, 411.4) | <.0001 |
Model 3‡
| 124.0 | (28.9, 219.0) | 0.01 |