Living alone, an important risk factor for cardiovascular disease

April 19, 2013 was the 116th birthday of Mr Jiroemon Kimura, the world's oldest living person. He was born on April 19, 1897 and Guinness World Records named him as the world's oldest person after the death of American woman Mrs Dina Manfredini on December 17, 2012. His motto to longevity is ‘to eat light and live long’. Mr Kimura has 14 grandchildren, 25 great-grandchildren, and 13 great-great-grandchildren, and his family celebrated and enjoyed his birthday with many relatives. It seems to me that people enjoying a long life-span such as centenarians have something in common. They have excellent daily habits, and they are physically active. More importantly, most centenarians are surrounded by dear families. In contrast, living alone may have an adverse impact on the course of diseases or health itself. There are several reports indicating that social isolation like living alone exerts adverse effects on the prognosis of coronary artery disease in the USA and other western countries; however, little is known regarding the impact of social factors on cardiovascular disease in Japan [1Case R.B. Moss A.J. Case N. McDermott M. Eberly S. Living alone after myocardial infarction. Impact on prognosis.J Am Med Assoc. 1992; 267: 515-519Crossref Scopus (405) Google Scholar, 2O'Shea J.C. Wilcox R.G. Skene A.M. Stebbins A.L. Granger C.B. Armstrong P.W. Bode C. Ardissino D. Emanuelsson H. Aylward P.E. White H.D. Sadowski Z. Topol E.J. Califf R.M. Ohman E.M. Comparison of outcomes of patients with myocardial infarction when living alone versus those not living alone.Am J Cardiol. 2002; 90: 1374-1377Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar, 3Schmaltz H.N. Southern D. Ghali W.A. Jelinski S.E. Parsons G.A. King K.M. Maxwell C.J. Living alone, patient sex and mortality after acute myocardial infarction.J Gen Intern Med. 2007; 22: 572-578Crossref PubMed Scopus (74) Google Scholar]. The structure of the Japanese society is quite different from Western countries. Statistics published by Japan's Ministry of Labor and Welfare indicates that the average life expectancy in Japan is 86.39 years for women and 79.64 years for men. In addition, the number of people aged 100 years or more surpassed 40,000 in 2008. Aging of society is a common problem in the world; however, Japan is aging at an unprecedented rate. Kitamura et al. clearly demonstrated that living alone is also an important risk factor for the prognosis of acute myocardial infarction in Japan [[4]Kitamura T. Sakata Y. Nakatani D. Suna S. Usami M. Matsumoto S. Hara M. Hamasaki T. Nanto S. Sato H. Hori M. Iso H. Komuro I. Living alone and risk of cardiovascular events following discharge after acute myocardial infarction in Japan.J Cardiol. 2013; 62: 257-262Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar]. They reported that acute myocardial infarction survivors living alone had a higher risk of cardiovascular events and death compared with those not living alone, by analysis of the Osaka Acute Coronary Insufficiency Study (OACIS), a large-scale, prospective, multicenter observation study in Japan. They found that living alone was independently associated with a higher risk of composite endpoint consisting of major adverse cardiovascular events and total deaths. Based upon their investigation, multivariate-adjusted hazard ratios of composite endpoint were 1.34 (95% confidence interval: 1.08–1.68) among male patients and 1.31 (95% confidence interval: 0.95–1.81) in the female patients. Recently, we examined the association of living alone and heart failure in elderly patients [[5]Kawai Y. Inoue N. Onishi K. Clinical picture and social characteristics of super-elderly patients with heart failure in Japan.Congest Heart Fail. 2012; 18: 327-332Crossref PubMed Scopus (7) Google Scholar]. To clarify the clinical picture and socioeconomic characteristics of super-elderly heart failure patients in our hospital, we divided 380 patients with acute heart failure or acutely worsening chronic heart failure into 3 groups according to age; patients aged less than 60 years, those aged from 60 to 80 years, and those aged 80 years or more (super-elderly group). We found that the social background was quite different for the 3 groups in several respects. In particular, the number of patients living alone increased with age. Thus, having family may be important for cardiovascular diseases in an aging society like Japan. Indeed, it is reported that marriage is an important predictor of survival after myocardial infarction in the short and long term [6Gerward S. Tydén P. Engström G. Hedblad B. Marital status and occupation in relation to short-term case fatality after a first coronary event—a population based cohort.BMC Public Health. 2010; 10: 235-242Crossref PubMed Scopus (25) Google Scholar, 7Chandra V. Szklo M. Goldberg R. Tonascia J. The impact of marital status on survival after an acute myocardial infarction: a population based study.Am J Epidemiol. 1983; 117: 320-325PubMed Google Scholar]. The mechanism whereby social isolation exerts adverse effects on long-term cardiovascular events remains to be elucidated; however, there are several possibilities. Social isolation including living alone may be associated with psychological factors including depression. So far, a lot of clinical investigations indicate a strong association between depression and adverse outcomes of coronary artery diseases. Depression is a well-known risk factor for various diseases including cardiovascular diseases, and especially, patients with myocardial infarction are vulnerable to depression [[8]Rosengren A. Hawken S. Ounpuu S. Sliwa K. Zubaid M. Almahmeed W.A. Blackett K.N. Sitthiamorn C. Sato H. Yusuf S. INTERHEART investigators Association of psychosocial risk factors with risk of acute myocardial infarction in 11119 cases and 13648 controls from 52 countries (the INTERHEART study): case–control study.Lancet. 2004; 364: 953-962Abstract Full Text Full Text PDF PubMed Scopus (1696) Google Scholar]. However, several clinical intervention trials have failed to demonstrate that successfully treating depression reduces the associated increased risk for cardiovascular diseases [[9]Berkman L.F. Blumenthal J. Burg M. Carney R.M. Catellier D. Cowan M.J. Czajkowski S.M. DeBusk R. Hosking J. Jaffe A. Kaufmann P.G. Mitchell P. Norman J. Powell L.H. Raczynski J.M. et al.Effects of treating depression and low perceived social support on clinical events after myocardial infarction: the Enhancing Recovery in Coronary Heart Disease Patients (ENRICHD) Randomized Trial.J Am Med Assoc. 2003; 289: 3106-3116Crossref PubMed Scopus (1514) Google Scholar]. On the other hand, social isolation tends to be associated with higher risk behaviors such as smoking or alcohol abuse. Indeed, in Kitamura's study, the frequency of drinking in the living alone group was significantly higher compared with that the group not living alone. Living alone may also be associated with poorer adherence with medication. These multiple factors could affect the clinical course and outcomes of cardiovascular diseases. In response to the aging society in Japan, the Japanese government started a public nursing care insurance system in April 2000. Under this system, a large number of elderly people can receive care services such as nursing at home, and day care or short stays at care houses. However, the present situation is not adequate for patients with cardiovascular diseases. There is a compelling need for fundamental enforcement of chronic care management and the establishment of measures for socially isolated patients. Although it seems to be difficult to investigate the effects of interventions targeting social isolation, such trials could provide a new insight into patient management of cardiovascular disease. The lack of social support in patients with cardiovascular diseases is a problem that needs to be resolved in Japan. Living alone and risk of cardiovascular events following discharge after acute myocardial infarction in JapanJournal of CardiologyVol. 62Issue 4PreviewLittle is known about the long-term risk of cardiovascular events after discharge among acute myocardial infarction (AMI) survivors living alone in Japan.