Association between social isolation and left ventricular mass.

BACKGROUND: Social isolation is associated with progression of cardiovascular disease, with the most socially isolated patients being at increased risk. Increased left ventricular mass is a predictor of cardiovascular morbidity and mortality. It is not yet clear whether social isolation is a determinant of increased left ventricular mass.
METHODS: We performed a cross-sectional study of Northern Manhattan Study participants who were free of clinical cardiovascular disease and had obtained transthoracic echocardiograms (n=2021) and a baseline questionnaire on social habits. Social isolation was defined as the lack of friendship networks (knowing fewer than 3 people well enough to visit within their homes). Echocardiographic left ventricular mass was indexed to height(2.7), analyzed as a continuous variable and compared between exposure groups.
RESULTS: The prevalence of social isolation was 13.5%. The average left ventricular mass was significantly higher (50.2 gm/m(2.7)) in those who were, as compared with those who were not (47.6 gm/m(2.7)), socially isolated (P<.05). Higher prevalence of social isolation was found among those less educated, uninsured, or unemployed. There were no significant race-ethnic differences in the prevalence of social isolation. In multivariate analysis, there was a trend toward an association between social isolation and increased left ventricular mass in the total cohort (P=.09). Among Hispanics, social isolation was significantly associated with greater left ventricular mass. Hispanics who were socially isolated averaged 3.9 gm/ht(2.7) higher left ventricular mass compared with those not socially isolated (P=.002). This relationship was not present among non-Hispanic blacks or whites.
CONCLUSION: In this urban tri-ethnic cohort, social isolation was prevalent and associated with indices of low socioeconomic status. Hispanics who were socially isolated had a greater risk for increased left ventricular mass.