A cohort study of reproductive risk factors, weight and weight change and the development of diabetes mellitus.
OBJECTIVE
Reproductive factors (parity, miscarriages, terminations), oral contraceptive use, hormone replacement therapy, body weight at first pregnancy and weight gain following pregnancy may be associated with a long-term risk of diabetes. The aim of this study is to investigate the independent risks of reproductive factors and body weight for diabetes in later life.


METHODS
This is a retrospective cohort study of 1257 parous women who had a first pregnancy between 1951 and 1970. Reproductive history, weight and height were measured at the time of first pregnancy, then assessed by questionnaire in 1997 for all women. A clinical examination and an analysis of blood samples were undertaken for 992 women. The main outcome was incidence of diabetes based on medical history, medication and random glucose measurement.


RESULTS
Sixty of the 1257 (4.8%) women developed diabetes. Body mass index at index pregnancy and after 28-48 years follow-up were both significantly associated with risk of diabetes, this increased with greater weight gain. There was a non-significant increased risk of diabetes associated with stillbirths and miscarriages after age and BMI adjustment.


CONCLUSIONS
In parous women, higher BMI at index pregnancy, weight gain during follow-up and BMI in later life strongly predict diabetes risk.
Dawson
S I
SI
Department of Public Health and General Practice, University of Otago, New Zealand.
Smith
W C S
WC
Watson
M S
MS
Wilson
B J
BJ
Prescott
G J
GJ
Campbell
D
D
Hannaford
P
P
D000028:Abortion, Induced; D000022:Abortion, Spontaneous; D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000009:adverse effects; D003920:Diabetes Mellitus / Q000209:etiology*; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy / Q000502:physiology*; D012189:Retrospective Studies; D012307:Risk Factors; D015430:Weight Gain / Q000502:physiology*
D003276:Contraceptives, Oral