Early-Onset Paternal Smoking and Offspring Adiposity: Further Investigation of a Potential Intergenerational Effect Using the HUNT Study

Abstract

Recently it has been suggested that rearing conditions during preadolescence in one generation may affect health outcomes in subsequent generations. Such parental effects, potentially induced by epigenetic modifications in the germ line, have attracted considerable attention because of their implications for public health and social policies. Yet, to date, evidence in humans has been rare due to data limitations and much further investigation in large studies is required. The aim of this paper is to reproduce and extend a recent study which found that paternal smoking before age 11 was associated with elevated body mass index (BMI) among male offspring in the Avon Longitudinal Study of Parents and Children (ALSPAC). Using the Nord-Trøndelag Health (HUNT) Study, we find that paternal smoking during pre-adolescence (<age 11) is not reliably or strongly associated with BMI among sons, with an estimated association close to zero (mean difference in kg m-2 (95% CI) was -0.18 (-1.75, 1.39) for sons aged 12–19 and 0.22 (-0.53, 0.97) for all ages). Among daughters, early-onset paternal smoking was imprecisely associated with an elevated BMI (mean difference was 1.50 (0.00, 3.00) for daughters aged 12–19 and 0.97 (0.06, 1.87) for all ages). Our results do not support a son-specific association of the magnitude reported in the ALSPAC study and we consider it improbable that early onset paternal smoking should influence specifically sons' BMI in one population and daughters' BMI in another. However, despite our considerable sample size (>45,000 offspring), we cannot rule out a weaker association, perhaps common to sons and daughters, which would be consistent with the ALSPAC study. Alternatively, we discuss whether confounding, chance in parallel tests, or sample selection effects might explain the observed associations of early paternal smoking with offspring BMI.

Paternal Programming of Liver Function and Lipid Profile Induced by a Paternal Pre-Conceptional Unhealthy Diet: Potential Association with Altered Gut Microbiome Composition

“…However, more recent studies showed that also paternal exposure to adverse environmental conditions can act on the offspring’s phenotype in terms of fetal programming and influence later life disease risk [11, 28]. Paternal programming has been likewise described in clinical observation studies [41, 42]. So far most of the animal studies dealing with paternal programming used paternal high-fat diet models prior to mating to investigate potential underlying mechanisms.…”

Parents’ smoking onset before conception as related to body mass index and fat mass in adult offspring: Findings from the RHINESSA generation study

“…Observations from the Överkalix and ALSPAC cohorts showed that excess food supply and smoking during mid-childhood and pre-pubertal years were associated with metabolic and cardiovascular health, and risk of becoming obese in subsequent generation(s) [ 16 – 19 ]. These findings remain to be successfully replicated, and there exists a possibility of residual confounding due to unmeasured family factors, especially due to the social patterning and inequalities related to smoking behaviour [ 20 , 21 ]. However, other epidemiological studies have reported adverse offspring outcomes related to paternal exposures in pre-puberty/puberty.…”

Smoking and pregnancy: Epigenetics and developmental origins of the metabolic syndrome

“…Children of smoking fathers were more likely to be overweight or obese at 5 years of age but not at 9 years in the Lifeways Cross‐generation Cohort study (Mejia‐Lancheros et al, ), and daughters whose fathers smoked during pregnancy were at higher risk of overweight and obesity in the study by Harris et al (), presumably due to secondhand smoke exposure of the mother. In contrast, a study specifically addressing the link between paternal early‐onset smoking and offspring BMI in the Nord‐Trøndelag Health (HUNT) cohort (Carslake, Pinger, Romundstad, and Davey Smith, ) did not find an association between paternal preadolescent smoking and sons' BMI yet reported a marginal relationship with daughters' BMI.…”