Objective: Blood pressure normally declines during the night (’dipping’); a blunted nocturnal decline is an important cardiovascular risk factor. Marriage may be associated with lower ambulatory blood pressure, although this may be confounded by socio-economic and dietary factors. We examined the association of marital status with nocturnal dipping and night-time SBP amongst individuals on a controlled diet.
Methods: We analysed 325 individuals enrolled in the Dietary Approaches to Stop Hypertension trial who had available 24-h SBP data and who ingested a control diet. Logistic and linear regression models were fit to estimate the association of marital status with nocturnal dipping and mean night-time SBP.
Results: Of the 325 individuals, 52.9% were men, the average age was 45.1 years and 48.9% reported being married. Compared with nonmarried individuals, those who were married had greater adjusted odds of dipping [odds ratio (OR) 2.26; 95% confidence interval (CI) 1.26–4.03; P = 0.01]. In adjusted models, being married was associated with lower night-time SBP (–2.4 mmHg; 95% CI –3.8 to –0.9 mmHg; P = 0.002), with the suggestion of a greater association in married men compared with married women (–3.1 vs. –1.7 mmHg); there was less difference for married nonblacks compared with married blacks (–2.7 and –2.4 mmHg, respectively).
Conclusion: Being married is independently associated with a greater likelihood of nocturnal dipping and with lower night-time SBP among individuals participating in a controlled dietary intervention; the association was particularly strong in married men. Marital status is a variable that may be considered in future analyses of ambulatory blood pressure.
aRenal Division, Department of Medicine, Brigham and Women's Hospital
bHarvard Medical School
cDepartment of Medicine, Brigham and Women's Hospital
dDepartment of Nutrition, Harvard School of Public Health
eChanning Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
Correspondence to Finnian Mc Causland, MB, MMSc, MRB-4, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02446, USA. Tel: +1 617 732 6432; fax: +1 617 732 6392; e-mail: firstname.lastname@example.org
Abbreviations: DASH, Dietary Approaches to Stop Hypertension; eGFR, estimated glomerular filtration rate
Received 26 June, 2013
Revised 6 December, 2013
Accepted 6 December, 2013