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Background: Type 2 diabetes is associated with low birthweight followed by obesity in adulthood. Persons who develop the disease may therefore have a particular pattern of growth from birth through childhood.Objective: To examine the relation of type 2 diabetes to size at birth and childhood growth.Design: Cohort study.Setting: Helsinki, Finland.Participants: Men (n = 3,639) and women (n = 3,447) who were bom at the Helsinki University Central Hospital between 1924 and 1933, who went to school in Helsinki, and who still lived in Finland in 1971. Detailed birth and school health records were available for all 7,086 participants. We identified 471 men and women who developed type 2 diabetes by using the national Social Insurance Institution's register of all persons in Finland who are receiving long-term therapy with medication.Measurements: Incidence of diabetes ascertained from a national register. The main explanatory measurements were size at birth and childhood growth in terms of height, weight, and body mass index.Results: The cumulative incidence of type 2 diabetes was 7.9% (n = 286) in men and 5.4% (n = 185) in women. The incidence increased with decreasing birthweight, birth length, ponderal index (birthweight/length(3)), and placental weight The odds ratio for type 2 diabetes was 1.38 (95% CI, 1.15 to 1.66; P < 0.001) for each 1-kg decrease in birthweight. The mean weights and heights of the children at 7 years of age who later developed type 2 diabetes were about average. Thereafter, their growth in weight and height was accelerated until 15 years of age. The odds ratio for development of type 2 diabetes was 1.39 (CI, 1.21 to 1.61; P < 0.001) for each standard deviation increase in weight between 7 and 15 years of age. The odds ratio became 1.83 (CI, 1.37 to 2.45; P< 0.001) in an analysis restricted to persons whose birthweights were below 3,000 g. Children of both sexes whose mothers had a high body mass index in pregnancy had more rapid growth during childhood and an increased incidence of type 2 diabetes.Conclusions: These findings are consistent with the hypothesis that type 2 diabetes is programmed in utero in association with low rates of fetal growth. The increased risk for type 2 diabetes associated with small size at birth is further increased by high growth rates after 7 years of age. [ABSTRACT FROM AUTHOR]

Context: Low birth weight is implicated as a risk factor for type 2 diabetes. However, the strength, consistency, independence, and shape of the association have not been systematically examined.Objective: To conduct a quantitative systematic review examining published evidence on the association of birth weight and type 2 diabetes in adults.Data Sources and Study Selection: Relevant studies published by June 2008 were identified through literature searches using EMBASE (from 1980), MEDLINE (from 1950), and Web of Science (from 1980), with a combination of text words and Medical Subject Headings. Studies with either quantitative or qualitative estimates of the association between birth weight and type 2 diabetes were included.Data Extraction: Estimates of association (odds ratio [OR] per kilogram of increase in birth weight) were obtained from authors or from published reports in models that allowed the effects of adjustment (for body mass index and socioeconomic status) and the effects of exclusion (for macrosomia and maternal diabetes) to be examined. Estimates were pooled using random-effects models, allowing for the possibility that true associations differed between populations.Data Synthesis: Of 327 reports identified, 31 were found to be relevant. Data were obtained from 30 of these reports (31 populations; 6090 diabetes cases; 152 084 individuals). Inverse birth weight-type 2 diabetes associations were observed in 23 populations (9 of which were statistically significant) and positive associations were found in 8 (2 of which were statistically significant). Appreciable heterogeneity between populations (I(2) = 66%; 95% confidence interval [CI], 51%-77%) was largely explained by positive associations in 2 native North American populations with high prevalences of maternal diabetes and in 1 other population of young adults. In the remaining 28 populations, the pooled OR of type 2 diabetes, adjusted for age and sex, was 0.75 (95% CI, 0.70-0.81) per kilogram. The shape of the birth weight-type 2 diabetes association was strongly graded, particularly at birth weights of 3 kg or less. Adjustment for current body mass index slightly strengthened the association (OR, 0.76 [95% CI, 0.70-0.82] before adjustment and 0.70 [95% CI, 0.65-0.76] after adjustment). Adjustment for socioeconomic status did not materially affect the association (OR, 0.77 [95% CI, 0.70-0.84] before adjustment and 0.78 [95% CI, 0.72-0.84] after adjustment). There was no strong evidence of publication or small study bias.Conclusion: In most populations studied, birth weight was inversely related to type 2 diabetes risk. [ABSTRACT FROM AUTHOR]