THE LIMACHE BIRTH COHORT STUDY IN CHILE

Background: By the seventies, the health and nutritional profile in Chile was of high infant mortality (>50/1000 live births) and high prevalence of nutritional and infectious diseases, but over a couple of decades birth weight increased markedly, malnutrition dropped to less than 1% and infant mortality fell to 14.6 by 1991. The current rate is 7/1000 live births. Objective: The Limache cohort aims at assessing life course events--cardiovascular risk factors and chronic respiratory conditions--under the Developmental Origins of Health and Disease (DOHaD) paradigm in two stages of development in Chile: before and after an unprecedented economic growth and remarkable epidemiological and nutritional change. Method: Ambidirectional follow-up study (non concurrent up to participants 22 years old, concurrent thereafter), with two birth cohorts born 12 years apart: Cohort A, a representative sample of 1232 subjects born between 1974 and 1978--impoverished prone period--in the main public hospital of Limache and measured at 22 to 28 years (2000-2002) and at 32 to 38 years (2010-2012); Cohort B (n=1000), a representative sample of new-borns between 1988- 1992--wealthier prone period--of mothers residing in the same counties, evaluated during at 22-28 (2014-2017). Equal methods were applied to register anthropometry at birth, over the first year and in adulthood, socioeconomic position (SEP), demographic and life style traits along with respiratory, cardiovascular and mental health parameters measured in each contact in adulthood. Results: Cohort A: Metabolic syndrome increased from 9.3% (95% CI:7.5-11.1) to 27.3 (95% CI: 25.0 to 31.0) from 1st to 2nd measurement, twofold for triglycerides, threefold for waist circumference and fivefold for blood glucose. People without risk factors fell from 32.5%; (95% CI:27.4-37.6) to 14.6% (95% CI:9.3- 19.9). Median BMI was 27.8 (IQR:25.0-31.1) at 2nd measurement, an increase of three units over 10 years. Increases were also ascertained in cardiovascular risk factors: glycaemia ≥110 mg/dL from 5 (95% CI:4-7) to 24% (95%CI:22 to 27); triglycerides ≥150 mg/ dL from 18 (95% CI:15-20) to 35.3% (95% CI:32.0-38.0); elevated waist circumference from 17 (95% CI:15-19) to 42% (95% CI:39- 45). We found inverse associations between birth weight and glycaemia, blood pressure, and cholesterol in adult life but not between birth weight and insulin resistance or metabolic syndrome. Also, there were no association between weight at 12 months a