Association of early-life undernutrition and risk of dyslipidemia in adulthood: a population-based cohort study

Abstract

Background: The association of early-life undernutrition and dyslipidemia found in previous studies may be confounded by the uncontrolled age difference between exposed and unexposed participants. The study aimed to investigate the association of early-life undernutrition and the risk of dyslipidemia in adulthood with good control of the age variable.

Methods: We took the Great Chinese Famine (1959-1961) as a natural experiment of severe undernutrition. This study was based on the baseline investigation of a population-based cohort in rural China. Undernutrition in early life was defined as being exposed to famine at younger than 3 years of age. Three approaches including Adjustment, Restriction, and Matching were applied to control the confounding effect of age. Logistic regression models were applied to evaluate the association between early-life famine and the presence of dyslipidemia. Stratified analysis by gender was also performed, and potential effect modification was tested by adding the interaction term of the famine exposure variable and gender into the model.

Results: Undernutrition in early life was associated with increased risk of borderline high and above (BHA) levels of total cholesterol (TC, OR_Adjustment = 1.61; OR_Restriction = 1.56; OR_Matching = 1.87), triglycerides (TG, OR_Adjustment = 1.33; OR_Restriction = 1.30; OR_Matching = 1.34), low-density lipoprotein cholesterol (LDL-C, OR_Adjustment = 1.75; OR_Restriction = 1.53; OR_Matching = 1.77) and dyslipidemia (OR_Adjustment = 1.52; OR_Restriction = 1.45; OR_Matching = 1.60), as well as high levels of TC, TG, LDL-C and dyslipidemia. An inverse association of undernutrition and risk of low high-density lipoprotein cholesterol (HDL-C) was found. Female participants with undernutrition experience had an increased risk of BHA TG and LDL-C (TG: OR_{Adjustment, female} = 1.45; OR_{Restriction, female} = 1.39; OR_{Matching, female} = 1.51; LDL-C: OR_{Adjustment, female} = 2.11; OR_{Restriction, female} = 1.80; OR_{Matching, female} = 2.15), but this association was not found in males.

Conclusion: Early-life undernutrition increased the risk of TC, TG, LDL-C, and dyslipidemia. Gender would significantly modify this effect for TG and LDL-C. These results emphasize the importance of nutritional conditions in the early stages of life to long-term health consequences.

Keywords: Confounding effect; Dyslipidemia; Great Chinese Famine; Undernutrition.