Transgenerational associations of parental famine exposure in early life with offspring risk of adult obesity in China

Early-life famine exposure, adulthood obesity patterns, and risk of low-energy fracture

Malnutrition in early life increases the risk of osteoporosis, but the association of early-life undernutrition combined with adulthood obesity patterns with low-energy fracture remains unknown. This study included 5323 community-dwelling subjects aged ⩾40 years from China. Early-life famine exposure was identified based on the participants' birth dates. General obesity was assessed using the body mass index (BMI), and abdominal obesity was evaluated with the waist-to-hip ratio (WHR). Low-energy fracture was defined as fracture occurring after the age of ⩾40 typically caused by falls from standing height or lower. Compared to the nonexposed group, the group with fetal, childhood, and adolescence famine exposure was associated with an increased risk of fracture in women with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.55 (1.57-8.05), 3.90 (1.57-9.71), and 3.53 (1.05-11.88), respectively, but not in men. Significant interactions were observed between fetal famine exposure and general obesity with fracture among women (P for interaction = 0.0008). Furthermore, compared with the groups with normal BMI and WHR, the group of women who underwent fetal famine exposure and had both general and abdominal obesity had the highest risk of fracture (OR, 95% CI: 3.32, 1.17-9.40). These results indicate that early-life famine exposure interacts with adulthood general obesity and significantly increases the risk of low-energy fracture later in life in women.

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.

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

BACKGROUND

Little is known about the transgenerational effect of nutrition deficiency in early life. This study aimed to evaluate the associations of fetal and childhood exposure to famine of parents with their offspring's risk of overweight during childhood.

METHODS

This analysis included a total of 3734 participants of the China Health and Nutrition Survey aged 1-17 years whose fathers and/or mothers were born in 1955-1966. These children were classified into subgroups according to parental famine exposure status (unexposed and exposed) and timing (fetal-exposed and childhood-exposed). Random effects models were applied to evaluate the associations of parental famine exposure with body mass index (BMI) and overweight of offspring. Fractional polynomial functions were adopted to describe trajectories of BMI against age.

RESULTS

Compared with children of unexposed parents, there was a lower risk of overweight among offspring of childhood-exposed fathers [OR (95%CI): 0.80 (0.61, 1.04)] or exposed parents [0.84 (0.68, 1.04)], particularly among male offspring, but not among those with exposed mothers only [0.98 (0.65, 1.47)]. For BMI, children with exposed mothers only had a slightly higher BMI [β(95%CI): 0.17 (-0.15, 0.49)], while those with exposed fathers only had no difference [-0.02 (-0.23, 0.19)] or exposed parents had a slightly lower BMI [-0.17 (-0.33, 0.00)] (p < 0.05 for interaction between maternal and paternal exposures). Stratified analysis showed little heterogeneity between male and female offspring, but the association between paternal childhood exposure to famine and lower overweight risk in offspring was more evident in high (vs low) paternal education group (p for interaction< 0.05).

CONCLUSIONS

The transgenerational associations of early-life exposure to famine with lower risks of child overweight may be via the paternal line and differ by the educational levels of parents. Further studies are warranted to confirm the results and reveal the biological mechanisms underlying.