Elevated risk of high blood pressure: climate and the inverse housing law.

BACKGROUND In previous work the authors identified an 'inverse housing law' in Britain such that housing quality tends to be worse in areas of harsh climate than in areas where the climate is more benign. This study investigates whether an individual's risk of hypertension is associated with such a 'mismatch' between the quality of their housing and the climate to which they have been exposed. METHODS Cross-sectional observational study based on Britain. Data came from the 5663 Health and Lifestyle Survey (HALS) participants for whom all relevant items were available. A two-stage study design was employed. First, the relationship between exposure to colder climate and housing quality was established. Second, the impact on risk of hypertension was determined for level of exposure to colder climate and housing quality. RESULTS Analysis confirmed that amongst survey respondents, those with greater exposure to colder climate are more likely (1.32, 95% CI: 1.18-1.42) to live in poor quality housing than those with lower exposure to colder climate. This combination of higher exposure to colder climate plus residence in worse quality housing raises significantly the risk of diastolic hypertension (1.45, 95% CI: 1.18-1.77) and, more weakly, systolic hypertension (1.25, 95% CI: 1.01-1.53). CONCLUSIONS There appears to be an 'inverse housing law' in Britain, whereby longer term residents of relatively cold areas are also more likely to live in worse quality housing and this combination of circumstances is associated with significantly higher risk of diastolic hypertension. The findings provide an example of how long term exposure to an adverse environment, which may stem from material disadvantage, can damage health.