Table 2.

Risk of type 2 diabetes in women with a history of gestational diabetes mellitus by number of optimal modifiable factors, based on data from the Nurses’ Health Study II (n=4275)

No of optimal modifiable factors‡	No of cases/person years	Absolute risk (No of cases/1000 person years)	Hazard ratio (95% CI)
			Model 1*	Model 2†
0	27/1349.3	20.0	1.00 (reference)	1.00 (reference)
1	310/15 895.7	19.5	0.96 (0.61 to 1.51)	0.94 (0.59 to 1.49)
2	361/28 558.3	12.6	0.61 (0.39 to 0.95)	0.61 (0.38 to 0.96)
3	175/26 671.0	6.6	0.31 (0.19 to 0.49)	0.32 (0.20 to 0.51)
4	46/13 883.3	3.3	0.15 (0.09 to 0.25)	0.15 (0.09 to 0.26)
5	5/2982.3	1.7	0.08 (0.03 to 0.22)	0.08 (0.03 to 0.23)
Ptrend§	—	—	<0.001	<0.001

CI=confidence interval.

^*Model 1 was adjusted for age (months).

^†Model 2 was adjusted for age, as well as race (white, non-white), parity (1, 2, ≥3), age at first live birth (<30, ≥30 years), total duration of breastfeeding (none to <1, 1-6, 6-12, >12 months), oral contraceptive use (never, former, current), menopausal status (pre-menopausal, post-menopausal), family history of diabetes in first degree relatives (yes, no), and total energy intake (divided by quartiles, kcal/day; 1 kcal=4.18 kJ).

^‡The optimal level of each factor was defined as follows: current non-smoker (including never or past smoker); body mass index <25.0; top two groups of the modified Alternate Healthy Eating Index score (divided by quintiles); ≥150 min/week of moderate intensity physical activity or ≥75 min/week of vigorous intensity physical activity; alcohol intake 5.0-14.9 g/day.

^§Number of optimal levels of modifiable risk factors was entered as a continuous variable into the model to estimate P value for trend.