Table 1.
Main effects of epidemiologic risk factors for renal cell carcinoma*
| Variable | Case subjects/control subjects | OR (95% CI) | P |
| Physical activity† | |||
| Intensive | 77/214 | Referent | |
| Medium | 124/200 | 1.65 (1.16 to 2.34) | .005 |
| Low | 251/165 | 4.08 (2.92 to 5.70) | <.001 |
| Ptrend | <.001 | ||
| Usual BMI‡ | |||
| Normal | 80/161 | Referent | |
| Overweight | 178/223 | 1.41 (0.98 to 2.03) | .07 |
| Obese | 207/201 | 1.50 (1.04 to 2.18) | .03 |
| Ptrend | .04 | ||
| BMI 3 years before diagnosis, continuous | 1.03 (1.01to1.05) | .01 | |
| BMI at age 20 years | |||
| Normal | 304/446 | Referent | |
| Overweight | 124/118 | 1.48 (1.08 to 2.05) | .02 |
| Obese | 34/21 | 1.92 (1.05 to 3.50) | .03 |
| Ptrend | .003 | ||
| BMI at age 20 years, continuous | 1.07 (1.03 to 1.11) | <.001 | |
| BMI at age 40 years | |||
| Normal | 145/265 | Referent | |
| Overweight | 180/220 | 1.40 (1.02 to 1.93) | .04 |
| Obese | 122/85 | 2.03 (1.38 to 2.98) | <.001 |
| Ptrend | <.001 | ||
| BMI at age 40 years, continuous | <.001 | ||
| Weight change, age 20–40 years§ | |||
| Weight loss > 0 lb | 24/28 | 1.70 (0.89 to 3.27) | .11 |
| Weight gain 0.1–10 lb | 109/204 | Ref. | |
| Weight gain 10.1–25 lb | 138/167 | 1.46 (1.02 to 2.09) | .04 |
| Weight gain >25 lbs. | 174/171 | 1.62 (1.10 to 2.39) | .01 |
| Ptrend | .09 | ||
| .03|| | |||
* For usual body mass index (BMI) (either categorized or continuous), BMI at age 20 years (either categorized or continuous), and BMI at age 40 years (either categorized or continuous), each variable was separately modeled with logistic regression and was adjusted for age, sex, smoking status, physical activity, and history of hypertension. For physical activity, the model was adjusted for age, sex, smoking status, history of hypertension, and usual BMI (category). All statistical tests were two-sided. CI = confidence interval; OR = odds ratio.
† Intensive: Metabolic equivalent value (MET) ≥ 45 per week; Medium: MET = 27–44.9 per week; Low: MET < 27 per week.
‡ Usual BMI refers to BMI 3 years before diagnosis or recruitment. Normal: <25kg/m2; Overweight: 25–29.9kg/m2; Obese: >30kg/m2.
§ The model for weight change was adjusted for age, sex, smoking status, usual BMI (category), history of hypertension, and physical activity, additionally adjusted for BMI at age 20 years (category).
|| The P value for dose–response trend is statistically significant if weight loss and subtle weight gain (0.1–10 lb) groups are collapsed into the reference group.