Snoring and hypertension: a 10 year follow-up

E. Lindberg, C. Janson, T. Gislason, K. Svärdsudd, J. Hetta, G. Boman
1998 European Respiratory Journal  
A number of surveys have addressed the issue of whether there is an association between snoring and hypertension. In many studies a significantly higher prevalence of hypertension has been found among habitual snorers than among nonsnoring individuals [1] [2] [3] [4] . However, snoring and hypertension have many risk factors in common. Cross-sectional and case-control studies have shown that snoring is associated with: obesity; age; smoking; heavy alcohol consumption; and physical inactivity
more » ... [6] [7] [8] [9] . After adjustments for these confounding factors, it was found in several recent studies that hypertension was not significantly associated with snoring [9] [10] [11] . In two review articles the authors have stated that there is no epidemiological evidence of a causal relationship between snoring and hypertension and one of the points they have criticized is the lack of prospective surveys within this field [12, 13] . To investigate whether habitual snoring is a risk factor for developing hypertension, a prospective, populationbased study was carried out with an observation period of 10 yrs. Materials and methods Population and study design The study population has been described in detail elsewhere [3, 14] . In short: in 1984, 4,021 males, aged 30-69 yrs, from the municipality of Uppsala, Sweden, were randomly selected for this epidemiological survey. A postal questionnaire was sent to all subjects, with a response rate of 79.6%. Of the 3,201 subjects who replied in 1984, 226 had died by October 1994. A new questionnaire was sent to the remaining 2,975 in November 1994. After two reminders, questionnaires that had been answered acceptably were returned by 2,668 subjects (89.7%). Questionnaires The questionnaire used in 1984 comprised 24 questions concerning somatic diseases, snoring and other sleep disturbances. A description of this questionnaire has been published previously [3, 14] . In the question about snoring, the subjects were asked to state the frequency of "loud and disturbing snoring", using a five-point scale. In the subsequent statistical evaluation, those subjects with scores of 1 (never), 2 (seldom) and 3 (sometimes) were regarded as nonhabitual snorers and those with scores of 4 (often) and 5 (very often) as habitual snorers. The terms persistent nonsnorers and persistent snorers were used to characterize those subjects who were in the same category in both 1984 and 1994. Questions were asked about body weight, height and body mass index (BMI, in kg·m -2 ) was calculated. The change in BMI (∆BMI) was calculated as BMI 1994-BMI 1984. ABSTRACT: In many cross-sectional studies an association has been found between snoring and hypertension. However, differing results have been obtained when confounding factors have been taken into account. To establish whether snoring is a risk factor for developing hypertension, a population-based, prospective survey was performed. In 1984 and 1994, 2,668 males, aged 30-69 yrs at baseline, answered questionnaires concerning sleep disturbances and somatic disease. Of the habitual snorers in 1984, 12.5% reported that they had developed hypertension during the period, compared with 7.4% of the remaining subjects (p<0.001). In a multiple logistic regression model persistent snoring, i.e., reported habitual snoring in both 1984 and 1994, was found to be an independent predictor for the development of hypertension among males aged 30-49 yrs (odds ratio 2.6, 95% confidence interval 1.5-4.5) after adjustments for age, body mass index (BMI), weight gain, smoking, alcohol dependence, and physical inactivity. Among the subjects aged 50-69 yrs in 1984, no association between snoring and development of hypertension was found. Although based only on reported data, the results indicate that persistent snoring is an independent risk factor for the development of hypertension among males aged <50 yrs. Prospective surveys, including whole-night sleep recordings, are needed to establish whether this is due to a higher prevalence of obstructive sleep apnoea syndrome among snorers or whether nonapnoeic snorers with increased upper airway resistance also have an increased risk of developing hypertension. Eur Respir J 1998; 11: 884-889.
doi:10.1183/09031936.98.11040884 pmid:9623692 fatcat:o6fncmpxovdj7mtf6mnsrglzim