Table 2.

Relative risk of Parkinson’s disease according to waist circumference and self-reported location of weight gain.

Variable	Category of variable distribution					p-trend §	p- heterogeneity^
	1	2	3	4	5
Waist Circumference in 1997 (inches*)
Men	<34.5	34.5-36.2	36.3-37.9	38.0-40.2	>=40.3
No. cases	31	48	20	72	78
No. PY	52356	74371	33559	118397	108195
RR1	1.0 (Ref)	1.07 (0.68, 1.68)	0.98 (0.56, 1.71)	1.01 (0.66, 1.54)	1.22 (0.81, 1.86)
RR2	1.0 (Ref)	1.07 (0.68, 1.69)	1.01 (0.57, 1.77)	1.10 (0.72, 1.69)	1.39 (0.91, 2.12)	0.08
Women	<28.0	28.0-29.9	30.0-31.9	32.0-34.9	>=35.0
No. cases	11	20	22	27	62
No. PY	41494	61427	72360	111956	187545
RR1	1.0 (Ref)	1.21 (0.58, 2.51)	1.10 (0.53, 2.28)	0.85 (0.42, 1.73)	1.19 (0.62, 2.26)
RR2	1.0 (Ref)	1.16 (0.55, 2.43)	1.06 (0.51, 2.20)	0.87 (0.43, 1.76)	1.26 (0.65, 2.41)	0.39
Men and Women
RR2		1.09 (0.74, 1.61)	1.03 (0.66, 1.61)	1.03 (0.72, 1.49)	1.35 (0.95, 1.93)	0.08	0.65
Self-reported location of weight gain		Peripheral weight gain £		Central weight gain £
Men
No. cases		154		266
No. PY		267571		511106
RR1		1.0 (Ref)		0.93 (0.76, 1.14)
RR2		1.0 (Ref)		0.91 (0.74, 1.11)		0.35
Women
No. cases		191		45
No. PY		781855		203994
RR1		1.0 (Ref)		0.85 (0.61, 1.17)
RR2		1.0 (Ref)		0.85 (0.61, 1.19)		0.35
Men and Women
RR2				0.89 (0.75, 1.06)		0.20	0.75

^*1 inch = 2.54 cm

¹*adjusted for age in months and smoking in quintiles of pack years

²*adjusted for age in months and smoking in quintiles of pack years, alcohol intake, caffeine intake, calories, dairy intake, pesticide exposure, physical activity, and education

^§trend tests conducted in multivariate models

^£central weight gain was defined as reported weight gain in the chest and shoulders or waist, and peripheral weight gain was defined as reported weight gain in hips and thighs or equally all over

^{^}p-heterogeneity comparing analyses including only men to those including only women