. Author manuscript; available in PMC: 2019 Jun 5.

Published in final edited form as: Diabetologia. 2017 Jan 7;60(5):836–842. doi: 10.1007/s00125-016-4200-4

Table 1. Baseline characteristics according to the season of birth among 461,211 participants.

Characteristics	Spring	Summer	Autumn	Winter
No. of participants	105,779	112,042	128,548	114,842
Age (years)	50.4 (10.4)	50.7 (10.4)^a	50.8 (10.5)^a	51.0 (10.6)
Rural area (%)	58.7^a	57.7	56.5	58.3^a
Married (%)	91.1^a	91.2^a	91.2^a	90.9^a
Middle school and higher (%)	49.6^abc	48.9	49.3^ab	49.7^ac
Daily smoker (%)	26.9^a	27.1^a	27.1^a	26.9^a
Weekly drinker (%)	15.2^a	15.3^a	15.3^a	15.0^a
Physical activity (MET-h/day) Weekly consumption^d	21.9 (13.9)^a	21.9 (14.0)^a	21.8 (14.0)^b	21.8 (13.9)^ab
Red meat (day)	3.69 (2.54)^abc	3.69 (2.53)^ab	3.71 (2.52)^abc	3.71 (2.51)^ac
Fresh vegetables (day)	6.83 (0.83)^a	6.84 (0.78)^a	6.84 (0.77)^a	6.84 (0.75)^a
Fresh fruits (day)	2.56 (2.48)^a	2.55 (2.46)^a	2.56 (2.48)^a	2.56 (2.47)^a
Postmenopausal (%)^e	48.8	49.2^a	49.4^a	49.2^a
Family history of diabetes (%)	9.2^a	9.1^a	9.0^a	9.2^a
Body mass index (kg·m^-2)	23.58 (3.35)^a	23.55 (3.35)^a	23.50 (3.30)^b	23.48 (3.31)^b
Waist circumference (cm)	80.0 (9.6)	79.8 (9.6)	79.6 (9.5)^a	79.6 (9.6)^a
Weight change since 25 years (kg)^f	4.8 (8.9)^a	4.8 (8.9)^a	4.6 (8.8)^b	4.5 (8.9)^b

Values are mean (standard deviation) unless otherwise stated. All variables were adjusted for age, sex, and survey sites, as appropriate.

^abc

Percentages or means sharing the same letter was not significantly different at Bonferroni-corrected level of significance. Bonferroni adjusted significance threshold was 0.008, based on six tests (pairwise comparison between four birth seasons).

Weekly consumptions of red meat, fresh vegetables, and fruits were calculated by assigning participants to the midpoint of their consumption category

Among 272,059 female participants

N=386,753

MET, metabolic equivalent of task