Table 2.

Incidence of early-onset type 2 diabetes and hazard ratio (CI95) according to exposure variables in the full cohort

	Cases	Person-years	Incidence rate*	Model 1	Model 2	Model 3
Sex
Women	1 633	8 457 221	19.31		1.00	1.00
Men	1 872	8 991 864	20.82		1.12 (1.04—1.19)	1.12 (1.05—1.20)
Year of birth
1983 to 1987	1 832	7 235 448	25.32		1.00	1.00
1988 to 1992	1 176	6 250 068	18.82		1.05 (0.96—1.14)	1.19 (1.09—1.30)
1993 to 1997	428	3 228 202	13.26		1.00 (0.88—1.13)	1.30 (1.15—1.47)
1998 to 2002	69	735 366	9.38		1.10 (0.85—1.42)	1.60 (1.23—2.07)
Family situation
Two-parent family	2 977	15 538 042	19.16	1.00	1.00	1.00
Single mother or another situation	307	875 154	35.08	1.83 (1.62—2.06)	1.24 (1.10—1.41)	1.21 (1.07—1.37)
Highest parental degree at the child’s birth
Up to compulsory education	571	1 459 330	39.13	3.54 (3.16—3.96)	2.14 (1.89—2.42)	1.81 (1.59—2.05)
Upper secondary	2 258	9 518 494	23.72	2.26 (2.07—2.46)	1.71 (1.56—1.88)	1.54 (1.41—1.69)
College/university	675	6 464 983	10.44	1.00	1.00	1.00
Parental country of birth
Both parents born in Sweden	2 723	14 399 265	18.91	1.00	1.00	1.00
Sweden-born mother only	235	940 577	24.98	1.35 (1.18—1.55)	1.19 (1.04—1.37)	1.14 (1.00—1.31)
Sweden-born father only	180	812 620	22.15	1.19 (1.02—1.38)	1.17 (1.00—1.36)	1.09 (0.94—1.27)
Both parents born outside Sweden	331	1 206 038	27.45	1.58 (1.41—1.78)	1.33 (1.18—1.50)	0.99 (0.88—1.12)
Lifetime diabetes history in the mother
No diabetes	2 416	16 213 281	14.90	1.00		1.00
History of diabetes	1 089	1 235 779	88.12	5.61 (5.21—6.04)		4.02 (3.68—4.38)
Lifetime diabetes history in the father
No diabetes	2 237	15 242 367	14.68	1.00		1.00
History of diabetes	1 232	2 116 135	58.22	3.75 (3.49—4.03)		3.16 (2.94—3.41)
Age of the mother at the child’s birth
< 20 years	199	482 875	41.21	2.29 (1.97—2.67)	1.67 (1.38—2.03)	1.84 (1.51—2.23)
≥ 20 to < 25 years	1 007	3 883 381	25.93	1.46 (1.34—1.59)	1.32 (1.17—1.49)	1.44 (1.28—1.63)
≥ 25 to < 30 years	1 180	6 468 308	18.24	1.06 (0.97—1.15)	1.10 (1.00—1.20)	1.18 (1.08—1.30)
≥ 30 years	1 119	6 614 521	16.92	1.00	1.00	1.00
Age of the father at the child’s birth
< 20 years	54	115 027	46.95	2.49 (1.90—3.26)	1.22 (0.90—1.66)	1.47 (1.09—1.99)
≥ 20 to < 25 years	535	1 958 707	27.31	1.45 (1.31—1.59)	0.99 (0.88—1.13)	1.15 (1.01—1.30)
≥ 25 to < 30 years	1 087	5 426 169	20.03	1.08 (1.00—1.17)	0.97 (0.89—1.06)	1.07 (0.98—1.17)
≥ 30 years	1 793	9 858 598	18.19	1.00	1.00	1.00
Maternal BMI in early pregnancy
< 18.5 kg/m2	107	774 751	13.81	0.79 (0.65—0.96)	0.65 (0.53—0.79)	0.68 (0.56—0.83)
≥ 18.5 and < 25 kg/m2	1 402	8 746 670	16.03	1.00	1.00	1.00
≥ 25 and < 30 kg/m2	557	1 813 525	30.71	2.16 (1.96—2.39)	1.99 (1.80—2.20)	1.54 (1.39—1.70)
≥ 30 kg/m2	276	477 259	57.83	4.60 (4.04—5.24)	3.67 (3.21—4.19)	2.34 (2.04—2.69)
Maternal diabetes during pregnancy
No	3 294	17 245 135	19.10	1.00	1.00	1.00
Yes	211	203 924	103.47	5.69 (4.95—6.56)	4.79 (4.15—5.53)	1.59 (1.36—1.85)
Maternal smoking during pregnancy
No smoking	1 813	12 194 972	14.87	1.00	1.00	1.00
Smoking	1 436	4 153 779	34.57	2.18 (2.03—2.34)	1.71 (1.58—1.84)	1.59 (1.48—1.71)
1 to 9 cigarettes per day	746	2 570 517	29.02	1.84 (1.69—2.01)	1.51 (1.38—1.65)	1.43 (1.31—1.56)
10 or more cigarettes per day	690	1 583 261	43.58	2.73 (2.50—2.99)	2.01 (1.83—2.21)	1.83 (1.67—2.02)
Infection during pregnancy
No	3 342	16 900 556	19.77	1.00	1.00	1.00
Yes	163	548 529	29.72	1.50 (1.28—1.75)	1.24 (1.06—1.46)	1.21 (1.03—1.41)
Pre-eclampsia
No	3 342	16 961 609	19.70	1.00	1.00	1.00
Yes	163	487 477	33.44	1.65 (1.41—1.93)	1.26 (1.07—1.49)	1.14 (0.96—1.34)
Birth order
1	1 487	7 162 640	20.76	1.00	1.00	1.00
2	1 104	6 241 830	17.69	0.85 (0.79—0.92)	0.97 (0.89—1.06)	0.96 (0.88—1.04)
≥ 3	914	4 044 616	22.60	1.08 (1.00—1.18)	1.13 (1.02—1.25)	1.04 (0.94—1.15)
Gestational age
Non-full-term birth (< 39 weeks)	1 034	4 155 016	24.89	1.32 (1.23—1.42)	0.96 (0.88—1.05)	0.94 (0.86—1.02)
Extremely to very preterm (≥ 22 to < 32 weeks)	51	91 662	55.64	3.03 (2.30—4.00)	1.17 (0.84—1.63)	1.15 (0.83—1.60)
Moderate to late preterm (≥ 32 to < 37 weeks)	255	790 902	32.24	1.70 (1.50—1.94)	0.95 (0.81—1.13)	0.93 (0.79—1.09)
Early birth term (≥ 37 to < 39 weeks)	728	3 272 452	22.25	1.18 (1.09—1.28)	0.96 (0.88—1.05)	0.94 (0.86—1.02)
Full term (≥ 39 weeks)	2 457	13 264 589	18.52	1.00	1.00	1.00
Birth weight
< 2500 g	264	567 773	46.50	2.95 (2.58—3.37)	2.40 (1.99—2.90)	2.38 (1.98—2.87)
≥ 2500 g and < 3500 g	1 733	7 484 730	23.15	1.48 (1.37—1.59)	1.42 (1.32—1.53)	1.43 (1.33—1.54)
≥ 3500 g and < 4500 g	1 367	8 742 745	15.64	1.00	1.00	1.00
≥ 4500 g	124	589 109	21.05	1.36 (1.13—1.63)	1.23 (1.02—1.47)	1.13 (0.94—1.36)
Size for gestational age**
Small for gestational age	245	461 832	53.05	2.78 (2.44—3.17)	2.31 (2.02—2.64)	2.24 (1.96—2.56)
Normal for gestational age	3 058	16 321 465	18.74	1.00	1.00	1.00
Large for gestational age	172	572 920	30.02	1.62 (1.39—1.90)	1.32 (1.13—1.55)	1.19 (1.01—1.39)
Mode of delivery
Vaginal delivery	3 017	15 555 373	19.40	1.00	1.00	1.00
C section	488	1 893 712	25.77	1.33 (1.21—1.47)	1.02 (0.92—1.13)	0.99 (0.89—1.09)

*For 100 000 person years

Model 1: each association with early-onset T2D is separately adjusted for sex and year of birth

Model 2: mutual adjustment for sex, year of birth, parental country of birth, parental highest educational level, family situation, parental age at delivery, maternal BMI, diabetes, smoking and infection during pregnancy, pre-eclampsia, birth order, gestational age, birth weight, and mode of delivery

Model 3: Model 2 + adjustment for parental lifetime history of diabetes

**In Model 2 and 3, size for gestational age was adjusted for the same variables except gestational age and birth weight