Background

The social and economic environment has become a major area of interest regarding the determinants of cardiovascular health. Among markers of economic distress, food insecurity has been found associated with metabolic disorders, dyslipidemia, and obesity, but no previous studies have examined its association with overall cardiovascular health.

Methods and results

We conducted a cross-sectional analysis among 2935 participants in the Survey of the Health of Wisconsin (SHOW), a statewide population-based representative sample. The presence of food insecurity was determined by an affirmative answer to the question "In the last 12months, have you been concerned about having enough food for you or your family?" Cardiovascular health (CVH) was defined based on the American Heart Association Life's Simple 7 criteria and classified as "poor," "intermediate," or "ideal" using previously published criteria. "Good" CVH was defined as having no poor in any of the seven criteria (any amount of intermediate or ideal). Crude and adjusted odds ratios (OR) of good CVH according to presence of food insecurity were calculated using logistic regression models. Overall, food insecurity was associated with a decreased likelihood of good CVH (OR 0.53; 95% Confidence Interval 0.31 to 0.92; p=0.02). This association persisted in models controlling for age, gender, race, and urbanization.

Conclusions

Participants who were food insecure were significantly less likely to have good CVH compared to participants who were food secure. Even though this study cannot confirm causality, these results suggest that food insecurity might be one of several socio-economic barriers contributing to poor CVH.

Objectives

Preterm births (PTBs) represent significant health risks, and several studies have found associations between high outdoor temperatures and PTB. We estimated both the total and natural direct effects (independent of particulate matter, ozone and nitrogen dioxide air pollutants) of the prior 2-day mean apparent temperature (AT) on PTB. We evaluated effect modification by maternal age, race, education, smoking status and prenatal care.

Design and setting

We obtained birth records and meteorological data for the Detroit, Michigan, USA area, for the warm months (May to September), 1991 to 2001. We used a time series Poisson regression with splines of AT, wind speed, solar radiation and citywide average precipitation to estimate total effects. To accommodate multiple mediators and exposure-mediator interactions, AT inverse odds weights, predicted by meteorological and air pollutant covariates, were added in a subsequent model to estimate direct effects.

Results

At 24.9°C relative to 18.6°C, 10.6% (95% CI: 3.8% to 17.2%) of PTBs were attributable to the total effects of AT, and 10.4% (95% CI: 2.2% to 17.5%) to direct effects. Relative excess risks of interaction indicated that the risk of PTB with increasing temperature above 18.6°C was significantly lower among black mothers and higher among mothers less than 19, older than 30, with late or no prenatal care and who smoked.

Conclusion

This additional evidence of a direct association between high temperature and PTB may motivate public health interventions to reduce extreme heat exposures among pregnant women, particularly among those who may have enhanced vulnerability.