Table 1 : Baseline characteristics* of participants according to
status of renal calculi in the EPIC-Potsdam Study.


         Renal calculi

Characteristics No
(n=21,845)
Yes
(n=2,645)
p value

Age, yrs 49.8±9.0 53.8±8.4 <0.001
Sex, % male 36.2 52.5 <0.001
Body mass index, kg/m2 26.3±0.0 26.7±0.1 <0.001

Waist circumference, cm

Men 94.7±0.1 95.4±0.3   0.01
Women 80.5±0.1 82.0±0.3 <0.001
Physical activity, h/wk 0.98±0.0 0.96±0.0   0.64

Smoking, % -- -- <0.001

Never 47.7 49.2   --
Former 31.4 34.0   --
Current, <20 cig/day 15.1 12.5   --
Current, ≥20 cig/day 5.9 4.3   --

Educational attainment, % -- --   0.38

No or vocational training 38.4 37.1   --
Technical school 24.6 25.6   --
Technical college, university 37.0 37.3   --
Alcohol intake, g/day 16.0±0.1 14.3±0.3 <0.001

Medical History, %      

Prevalent hypertension 47.3 54.8 <0.001
Prevalent diabetes 4.8 5.9   0.01

Nutritional factors      

Water, ml/day 418±3.1 486±8.6 <0.001
Fruits and vegetables 191±0.8 195±2.3   0.07
Red meat, g/day 30.2±0.1 30.5±0.4   0.39
Processed meat, g/day 61.5±0.3 60.6±0.8   0.28
Fat, g/day 82.7±0.1 82.8±0.3   0.66
Cholesterol, mg/day 307±0.6 304±1.6   0.15

Biomarkers§, mg/dl No
(n=1,852)
Yes
(n=216)
p value

hsCRP 1.80±0.1 1.96±0.2   0.49
Triglycerides 130±2.1 134±5.8   0.59
Total cholesterol 191±1.0 197±2.8   0.04
HDL cholesterol 51.7±0.3 50.9±0.9   0.43
Uric acid 4.50±0.0 4.68±0.1   0.03

Abbreviations: cig.: cigarettes, EPIC: European Investigation into Cancer and
Nutrition, HDL: high.density lipoprotein, hsCRP: high-sensitivity C-reactive protein
*Baseline characteristics of participants are expressed as age- and sex-adjusted
means±standard error (SE) or percentages and were compared between
participants with and without stones using analysis of covariance. Age and sex
were not adjusted and are expressed as mean ± standard deviation or percentage.
Age and gender distribution were compared between participants with and
without stones using Student's unpaired t test or the x2 test, respectively.
Nutritional intakes are expressed as means ± SE, adjusted for age, sex and total
energy intake.
§Based on a randomised subcohort of the EPIC-Potsdam study.

Wirth et al.Clinical Nephrology and Urology Science  2014 1:3DOI : 10.7243/2054-7161-1-3