Depressive symptom clusters and optimistic traits are associated with left ventricular mass increase in older subjects independently of blood pressure levels and hypertension

Depression is an independent risk factor for cardiovascular (CV) diseases, comparable in strength with that of traditional risk factors.1 Older subjects have increased prevalence and poorer control of hypertension. Depression might be accompanied by increased left ventricular mass (LVM) regardless of blood pressure (BP) levels.3-5 Specific depressive symptoms can be more predictive of CV diseases than others.6-8 The present preliminary study investigated whether specific clusters of depressive symptoms were associated with increased LVM in older subjects, independently of BP levels and other risk factors. Older community-dwellers referred for evaluation of hypertension to our outpatient clinic (Merry House, Division of Geriatrics) were consecutively studied. Exclusion criteria were: fifth edition of the Diagnostic and Statistical Manual of Mental Disorders-defined dementia, neuropsychiatric diagnoses other than depression, clinical CV diseases (stroke, transient ischemic attack, myocardial infarction, angina pectoris), heart valve diseases, arrhythmias, diabetes mellitus and current smoking. Physical and laboratory examinations were carried out. Left ventricular diameter (LVDd), left ventricular posterior wall thickness (PWTd) and interventricular septum thickness (IVTd) at end-diastole were determined through standard echocardiography, using a Toshiba ultrasound machine. LVM was determined using the Devereux formula (LVM [g] = 1.04 [{LVDd + PWTd + IVTd} × 3 – {LVDd} × 3] – 13.6) and normalized for body height to the 2.7 as left ventricular mass index (LVMI; g/m2.7).2 Left ventricular hypertrophy (LVH) was defined as LVMI >50 g/m2.7. The 30-item Geriatric Depression Scale (GDS), whose details are described elsewhere, was administered. Items were grouped into four symptom clusters: (i) dysphoria (11 questions); (ii) apathy (6 questions); (iii) meaninglessness (7 questions); and (iv) subjective cognitive complaints (6 questions), according to previous analyses.9 Depression was defined by GDS score >10. Optimistic traits were assessed using the short form of the Life Optimism Test Questionnaire:10 (i) Are you always optimistic about future?; and (ii) Do you rarely expect things to go your way? (reverse score), either scored 1–5 (comprehensive score ranging from 2 to 10), the higher the score the higher the level of optimism. Statistical analysis was carried out by spss 17.0 for Windows (SPSS, Chicago, IL, USA). Continuous and dichotomous variables were compared according to the presence of depression, using Student's unpaired t-test and χ2-statistic. GDS subscales and optimism scores were compared across LVMI tertiles (Fig. 1). Symptom clusters were tested in stepwise linear regression models as determinants of LVH. Statistical significance was set for P-values ≤0.05. Distribution of depressive symptom clusters and optimism (mean ± SD) across left ventricular mass index (LVMI; g/m2.7) tertiles. A total of 68 participants (67.0% women) aged 79.5 ± 8.0 years were studied. Of these, 52 were receiving antihypertensive treatment and five were receiving antidepressive treatment. Depressed participants (n = 28) had higher body mass index (P = 0.008) and lower high-density lipoprotein cholesterol (P = 0.03) than controls. Despite similar BP levels and duration of hypertension, patients with depression had greater LVMI (58.4 ± 6.2 vs 47.6 ± 8.2 g/m2.7, P < 0.001). There were no differences in age, sex, glucose, CV drugs use and left ventricular ejection fraction. GDS scores linearly increased across LVMI tertiles (7.0 ± 4.5 vs 14.6 ± 8.7 vs 20.3 ± 6.3 from lower to higher tertile, P < 0.001). Figure 1 shows the distribution of symptom clusters and optimism across LVMI tertiles. By multiple regression models, dysphoria (OR 6.12, 95% CI 3.00–12.71) and optimism (OR 0.27, 95% CI 0.11–0.68) were the only independent determinants of LVH after stepwise multiple adjustment including age, sex, glucose, total and high-density lipoprotein cholesterol, BP levels and duration of hypertension. This is the first report describing an association between depressive symptom clusters and LVM changes in older individuals. Our results suggest that the relationship between depression and increased LVM might be driven by symptoms of dysphoria and pessimistic traits. Depression is a multidimensional construct, consisting of affective, cognitive, behavioral and somatic dimensions. It is surprising that little research has been carried out in examining whether specific dimensions differently contribute to CV diseases.1, 6, 7 Few studies focused on the association with incident coronary heart disease, showing conflicting results; authors have shown that somatic symptoms are the most predictive of coronary heart disease, others reporting similar results for depressed affect cluster, hopelessness and pessimism.1, 6, 7 Although it is difficult to draw strong inferences, it remains the key hypothesis that specific facets of depression might be more “cardiotoxic” than others. Therefore, specific dimensions of depression could have a stronger impact on LVM in older patients, independently of BP levels and other risk factors. Screening and characterization of depressive symptoms in the older population might help in identifying individuals with greater risk of having LVH and, therefore, increased risk for CV events. A potential weakness of the present study was that LMV assessment was based on echocardiography. Although this method is the most widely used in clinical practice, it is not the most accurate in assessing LVM when compared with other techniques, such as cardiac magnetic resonance. Future studies are required to better characterize mechanisms underlying such associations. We suggest that specific dimensions of depression could have a greater impact on the neuroautonomic system, leading to increased sympathetic response and accelerated CV end-organ damage. Furthermore clinicians should be aware that specific depression patterns might be associated with reduced adherence to therapies. Giovanni Viscogliosi and Evaristo Ettorre conceived and wrote the paper. Iulia Maria Chiriac, Franca Pellegrini, Flavio Brutti and Paola Andreozzi reviewed the current literature, and carried out neuropsychological studies and statistical analyses. Carlo Bellomi carried out echocardiography. No potential conflicts of interest were disclosed.