Loneliness in older adults is associated with functional decline, depression and even death. Given the prevalence of loneliness, the aim of this study was to examine the association between loneliness and cardiac biomarkers in older people that attend to cardiology consultation. The results showed that loneliness was more prevalent in women than in men, and it was associated with marital status too. ECG recording were analyzed and QT interval and T-wave length showed higher values in people suffering from loneliness, as well as higher cardiac frequency, where the presence of meaning in life be a protective factor. Studies with a larger sample size are needed, but these results appear to show a relationship between biomarkers and mental state.