Parental exposure to famine in early life and child overweight in offspring in Chinese populations

Intrauterine arsenic exposure induces glucose metabolism disorders in adult offspring by targeting TET2-mediated DNA hydroxymethylation reprogramming of HNF4α in developing livers, an effect alleviated by ascorbic acid

Exposure to arsenic during gestation has lasting health-related effects on the developing fetus, including an increase in the risk of metabolic disease later in life. Epigenetics is a potential mechanism involved in this process. Ten-eleven translocation 2 (TET2) has been widely considered as a transferase of 5-hydroxymethylcytosine (5hmC). Here, mice were exposed, via drinking water, to arsenic or arsenic combined with ascorbic acid (AA) during gestation. For adult offspring, intrauterine arsenic exposure exhibited disorders of glucose metabolism, which are associated with DNA hydroxymethylation reprogramming of hepatic nuclear factor 4 alpha (HNF4α). Further molecular structure analysis, by SEC-UV-DAD, SEC-ICP-MS, verified that arsenic binds to the cysteine domain of TET2. Mechanistically, arsenic reduces the stability of TET2 by binding to it, resulting in the decrease of 5hmC levels in Hnf4α and subsequently inhibiting its expression. This leads to the disorders of expression of its downstream key glucose metabolism genes. Supplementation with AA blocked the reduction of TET2 and normalized the 5hmC levels of Hnf4α, thus alleviating the glucose metabolism disorders. Our study provides targets and methods for the prevention of offspring glucose metabolism abnormalities caused by intrauterine arsenic exposure.

Exposure to Chinese famine in early life and height across 2 generations: a longitudinal study based on the China Health and Nutrition Survey

BACKGROUND

Poor nutrition early in life is associated with short stature, which is associated with increased risk of cardiovascular disease and mortality in later life. Less evidence is available about the impact of early-life nutrition on height growth in the subsequent generation.

OBJECTIVES

This study investigated the associations of famine exposure in utero and early childhood with height across 2 generations.

METHODS

We used longitudinal data from the China Health and Nutrition Survey. We included 5401 participants (F1) born in 1955-1966 (calendar year around the Chinese famine in 1959-1961) and their 3930 biological offspring (F2). We classified F1 participants into subgroups by famine exposure status (unexposed/exposed) and timing (fetal-/childhood-exposed) according to their birth year and grouped F2 by their parents' exposure. Linear regression models were applied to examine the associations of famine exposure with adult height of F1 and F2. Linear mixed effect models with fractional polynomial functions were performed to estimate the difference in height between exposure groups of F2 during childhood.

RESULTS

Participants (F1) exposed to famine in utero or in childhood were shorter than those unexposed by 0.41 cm (95% CI: 0.03, 0.80) and 1.12 cm (95% CI: 0.75, 1.48), respectively. Offspring (F2) of exposed fathers were also shorter than those of unexposed parents by 1.07 cm (95% CI: 0.28, 1.86) during childhood (<18 y) and by 1.25 cm (95% CI: 0.07, 2.43) in adulthood (≥18 y), and those with exposed parents had a reduced height during childhood by 1.29 cm (95% CI: 0.68, 1.89) (all P values < 0.05). The associations were more pronounced among child offspring of highly-educated F1, particularly for paternal exposure and among female offspring (all P for interaction < 0.05).

CONCLUSIONS

The findings support the intergenerational associations of famine exposure in early life with height in Chinese populations, indicating the public health significance of improving the nutritional status of mothers and children in the long run.