Noise-induced hearing loss (NIHL) is one of the most important occupational health hazards. Millions of people worldwide are exposed daily to harmful levels of noise. NIHL is a complex disease resulting from an interaction between genetic and environmental factors. Although the environmental risk factors have been studied extensively, little is known about the genetic factors. Heat-shock proteins (HSPs) are induced after exposure to severe noise. When first induced by exposure to moderate sound levels, they can protect the ear from damage from excessive noise exposure. This protection is highly variable between individuals. An association of HSP70 genes with NIHL has been described by Yang et al (2006) in a Chinese sample set of noise-exposed workers. In this study, three polymorphisms (rs1043618, rs1061581 and rs2227956) in HSP70-1, HSP70-2 and HSP70-hom, respectively, were genotyped in 206 Swedish and 238 Polish DNA samples of noise-exposed subjects and analyzed. One SNP, rs2227956 in HSP70-hom, resulted in a significant association with NIHL in both sample sets. In addition, rs1043618 and rs1061581 were significant in the Swedish sample set. Analysis of the haplotypes composed of the three SNPs revealed significant associations between NIHL and haplotype GAC in both sample sets and with haplotype CGT in the Swedish sample set. In conclusion, this study replicated the association of HSP70 genes with NIHL in a second and third independent noise-exposed sample set, hereby adding to the evidence that HSP70 genes may be NIHL susceptibility genes.

Reducing postpartum weight retention is a promising strategy for addressing the rising prevalence of overweight and obesity in women. This systematic review and meta-analysis explored whether lifestyle interventions during pregnancy have the potential to reduce weight retention at 4 months postpartum and beyond. A search of five electronic databases for randomized controlled trials comparing the effect of weight-related lifestyle interventions beginning in pregnancy on postpartum weight retention to standard prenatal care groups was performed. Postpartum weight retention data was synthesized in a random-effects meta-analysis. Data from 14 studies of 7116 participants showed that the intervention group retained statistically significant less weight than the control group (weighted mean difference: −0.73 kg, 95% CI: −1.32 to −0.14, P = 0.015). Subgroup analysis showed this effect to be largest in studies with follow-ups from 4 to 6 months (weighted mean difference: −1.32 kg, 95% CI: −2.11 to −0.53, P = 0.001), but it remained significant until 12 months postpartum (weighted mean difference: −0.68 kg, 95% CI: −1.28 to −0.09, P = 0.023). In studies of women with a body mass index above 25.0 kg/m 2 , no significant intervention effect was observed. More high-quality studies with a follow-up beyond 12 months postpartum are needed.

Background Maternal health and lifestyle during pregnancy may be critical for the onset and progression of childhood obesity. Prenatal lifestyle interventions have been shown to positively affect maternal behaviors, gestational weight gain, and anthropometric outcomes in infants at birth. The influence of such interventions on child weight or growth beyond birth is unknown. We therefore examined the association between lifestyle interventions during pregnancy and anthropometric outcomes during childhood. Methods A systematic literature search was conducted in three electronic databases, two clinical trial registers and further sources, without language or publication status restrictions. Additionally, 110 study authors were contacted to obtain unpublished data. Randomized controlled trials comparing any antenatal lifestyle or behavioral intervention to standard prenatal care, in women of any body mass index (BMI), with offspring anthropometric data at 1 month of age or older, were considered. Two reviewers independently extracted data and assessed the risk of bias using the Cochrane Collaboration’s updated tool. Data on weight, length, and BMI, and corresponding z-scores, were stratified into six age ranges and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated in univariate and multivariate random-effects meta-analytical models. Results Twenty trials comprising 11,385 women were included in this systematic review, of which 19 were combined in meta-analyses. Overall, lifestyle interventions during pregnancy were not associated with differences in weight, length, BMI, or corresponding z-scores, in children aged 1 month to 7 years (e.g. weight in 5 to 6 month old children, WMD: 0.02 kg; 95% CI: − 0.05 to 0.10 kg, I2 = 38%; 13 studies, 6667 participants). Findings remained consistent when studies were stratified by maternal baseline BMI or other risk factors, and intervention content and duration. Based on the GRADE criteria, the strength of the body of evidence was considered moderate. Conclusion Prenatal lifestyle interventions were not shown to influence childhood weight or growth. Nevertheless, women should be encouraged to pursue a healthy lifestyle during pregnancy. Further efforts to establish early prevention strategies for childhood obesity are urgently needed. Thus, large, high-quality studies with pre-planned, long-term follow-ups are warranted. Trial registration PROSPERO CRD42018118678.