Sleep Apnea in Idiopathic Pulmonary Fibrosis: A Molecular Investigation in an Experimental Model of Fibrosis and Intermittent Hypoxia

BACKGROUND

High prevalence of obstructive sleep apnea (OSA) is reported in incident and prevalent forms of idiopathic pulmonary fibrosis (IPF). We previously reported that Intermittent Hypoxia (IH), the major pathogenic element of OSA, worsens experimental lung fibrosis. Our objective was to investigate the molecular mechanisms involved.

METHODS

Impact of IH was evaluated on C57BL/6J mice developing lung fibrosis after intratracheal instillation of Bleomycin (BLM). Mice were Pre-exposed 14 days to IH before induction of lung fibrosis or Co-challenged with IH and BLM for 14 days. Weight loss and survival were daily monitored. After experimentations, lungs were sampled for histology, and protein and RNA were extracted.

RESULTS

Co-challenge or Pre-exposure of IH and BLM induced weight loss, increased tissue injury and collagen deposition, and pro-fibrotic markers. Major worsening effects of IH exposure on lung fibrosis were observed when mice were Pre-exposed to IH before developing lung fibrosis with a strong increase in sXBP1 and ATF6N ER stress markers.

CONCLUSION

Our results showed that IH exacerbates BLM-induced lung fibrosis more markedly when IH precedes lung fibrosis induction, and that this is associated with an enhancement of ER stress markers.

Adherence to the 2017 French dietary guidelines and adult weight gain: A cohort study

BACKGROUND

The French dietary guidelines were updated in 2017, and an adherence score to the new guidelines (Programme National Nutrition Santé Guidelines Score 2 [PNNS-GS2]) has been developed and validated recently. Since overweight and obesity are key public health issues and have been related to major chronic conditions, this prospective study aimed to measure the association between PNNS-GS2 and risk of overweight and obesity, and to compare these results with those for the modified Programme National Nutrition Santé Guidelines Score (mPNNS-GS1), reflecting adherence to 2001 guidelines.

METHODS AND FINDINGS

Participants (N = 54,089) were recruited among French adults (≥18 years old, mean baseline age = 47.1 [SD 14.1] years, 78.3% women) in the NutriNet-Santé web-based cohort. Mean (SD) score was 1.7 (3.3) for PNNS-GS2 and 8.2 (1.6) for mPNNS-GS1. Selected participants were those included between 2009 and 2014 and followed up to September 2018 (median follow-up = 6 years). Collected data included at least three 24-hour dietary records over a 2-year period following inclusion, baseline sociodemographics, and anthropometric data over time. In Cox regression models, PNNS-GS2 was strongly and linearly associated with a lower risk of overweight and obesity (HR for quintile 5 versus quintile 1 [95% CI] = 0.48 [0.43-0.54], p < 0.001, and 0.47 [0.40-0.55], p < 0.001, for overweight and obesity, respectively). These results were much weaker for mPNNS-GS1 (HR for quintile 5 versus quintile 1 = 0.90 [0.80-0.99], p = 0.03, and 0.98 [0.84-1.15], p = 0.8, for overweight and obesity, respectively). In multilevel models, PNNS-GS2 was negatively associated with baseline BMI and BMI increase over time (β for a 1-SD increase in score [95% CI] = -0.040 [-0.041; -0.038], p < 0.001, and -0.00080 [-0.00094; -0.00066], p < 0.001, respectively). In "direct comparison" models, PNNS-GS2 was associated with a lower risk of overweight and obesity, lower baseline BMI, and lower BMI increase over time than mPNNS-GS1. Study limitations include possible selection bias, reliance on participant self-report, use of arbitrary cutoffs in data analyses, and residual confounding, but robustness was tested in sensitivity analyses.

CONCLUSIONS

Our findings suggest that adherence to the 2017 French dietary guidelines is associated with a lower risk of overweight and obesity. The magnitude of the association and the results of the direct comparison reinforced the validity of the updated recommendations.

TRIAL REGISTRATION

The NutriNet-Santé Study ClinicalTrials.gov (NCT03335644).

Associations between transition to retirement and changes in dietary intakes in French adults (NutriNet-Santé cohort study)

BACKGROUND

Few studies have focused on the influence of retirement on dietary behaviors. Our study aimed at assessing the associations between transition to retirement and changes in dietary intake in French adults, particularly according to spousal retirement and baseline income.

METHODS

This prospective study included 577 French participants from the NutriNet-Santé cohort who retired over a 5-year follow-up (2009-2014 or 2010-2015). At baseline and every year, dietary intakes were assessed using 24 h records. Repeated measures of dietary intake were analysed using mixed models adjusted for energy with random effects of time and period (before and after retirement) to assess changes following retirement for each gender.

RESULTS

After retirement, intakes of saturated fatty acids and sodium increased in both genders. Women showed specific changes after retirement: decrease in the score of adherence to recommendations and in intakes of fruits, proteins, vitamins; increase in intakes of fatty sweet products. In men with the lowest income at baseline, specific changes in intake were associated with retirement such as decrease in intake of dairy products and increase in intake of lipids.

CONCLUSIONS

Transition to retirement was associated with unhealthier dietary intakes. These results may help defining interventions during this vulnerable life-period.

TRIAL REGISTRATION

This study was conducted according to guidelines laid down in the Declaration of Helsinki and all procedures were approved by the Institutional Review Board of the French Institute for Health and Medical Research (IRB Inserm No. 0000388FWA00005831) and the French Data Protection Authority (Commission Nationale Informatique et Libertés No. 908450 and No. 909216). Electronic informed consents were obtained from all participants.