Improving the identification and treatment of depression in women after acute myocardial infarction

We read with interest the article by Smolderen et al (1), which reported real-world lessons from the implementation of an American Heart Association (AHA) recommended depression screening protocol in Acute Myocardial Infarction (AMI) patients. After implementing a routine, two- step depression screening process using the Patient Health Questionnaire (PHQ) 2 and 9, the study revealed that more than 1 in 4 (n=135, 26.8%) Coronary Artery Disease (CAD) patients failed to be screened for depression. Specifically, women were likely to be missed. Of those who were screened, almost 7 of 10 patients with significant depressive symptoms failed to be recognized and thus were ineligible for treatment.

Raised CRP levels in obese patients : symptoms of depression have an independent positive association

Background: Depression and obesity, the two common ailments of modern society, are associated with increased risk of coronary artery disease and raised C-reactive protein (CRP) levels. Are the effects of depression and obesity related or do they influence CRP levels independently?

Objective: In 493 consecutive patients presenting for obesity surgery, we explored the relationship between symptoms of depression and raised CRP levels after controlling for confounding factors.

Methods and Procedures: Depression was measured using the Beck Depression Inventory (BDI). Confounding variables were age, gender, BMI, waist and hip measures, smoking and alcohol habits, medications, biochemical measures of the metabolic syndrome, and indirect measures of insulin resistance. General linear regression sought variables independently associated with CRP levels.

Results: These patients had a BMI range from 31 to 91 kg/m2, participants age ranged from 14 to 71 years, and 76% were women. The median CRP concentration was 7.7 mg/l (interquartile range: 3.9–14), 40% had an abnormally raised concentration (>10 mg/l). The mean BDI score was 17.0 ± 9.0, indicating symptoms of moderate depression. We found five independent factors associated with raised CRP levels. In order of strength of association, these were: higher BMI (β = 0.36, P < 0.001), female gender (β = −0.19, P < 0.001), estrogen therapy (β = 0.18, P < 0.001), higher BDI score (β = 0.11, P = 0.01), and insulin resistance index (β = 0.11, P = 0.01), and with a combined R 2 = 0.24, (P < 0.001). Discussion: In obese patients, symptoms of depression were associated with raised CRP levels after controlling for confounding variables. Obese women on estrogen therapy are at risk of high CRP levels.

Prevention of diabetes in rural India with a telemedicine intervention

Background : Diabetes care is not presently available, accessible, or affordable to people living in rural areas in developing countries, such as India. The Chunampet Rural Diabetes Prevention Project (CRDPP) was conceived with the aim of implementing comprehensive diabetes screening, prevention, and treatment using a combination of telemedicine and personalized care in rural India.

Methods : This project was undertaken in a cluster of 42 villages in and around the Chunampet village in the state of Tamil Nadu in southern India. A telemedicine van was used to screen for diabetes and its complications using retinal photography, Doppler imaging, biothesiometry, and electrocardiography using standardized techniques. A rural diabetes center was set up to provide basic diabetes care.

Results : Of the total 27,014 adult population living in 42 villages, 23,380 (86.5%) were screened for diabetes, of which 1138 (4.9%) had diabetes and 3410 (14.6%) had prediabetes. A total of 1001 diabetes subjects were screened for complications (response rate of 88.0%). Diabetic retinopathy was detected in 18.2%, neuropathy in 30.9%, microalbuminuria in 24.3%, peripheral vascular disease in 7.3%, and coronary artery disease in 10.8%. The mean hemoglobin A1c levels among the diabetes subjects in the whole community decreased from9.3 ± 2.6% to 8.5 ± 2.4% within 1 year. Less than 5% of patients needed referral for further management to the tertiary diabetes hospital in Chennai.

Health impacts of eicosapentaenoic acid and docosahexaenoic acid

Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) particularly, eicosapentaenoic acid (EPA, 22: 5n-3) and docosahexaenoic acid (DHA, 22: 6n-3) have been reported to reduce the risks of cardiovascular disease (CVD) including myocardial infarction, stroke, coronary artery disease and sudden cardiac death. In addition, these fatty acids play an important role in reduction of cancer risks, Alzheimer's disease, depression and schizophrenia. Furthermore, studies also showed that EPA and DHA are important for foetal development, particularly neuronal and retinal functions. Several recent human trials have strengthened the evidence that EPA and DHA can reduce the risks of various chronic diseases although this has not been a uniform finding. In general, the high prevalence of mortality caused by chronic disease can be prevented by consumption of LC n-3 PUFA, which has been proven to have considerable health benefits. The aim of this paper was to review main scientific evidence regarding the health impact of LC n-3 PUFA, especially EPA and DHA on chronic disease including CVD, cancer, mental health, arthritis and infant development.

Altered cardiac autonomic nervous function in depression

Background:
Depression is an independent risk factor for coronary artery disease. Autonomic instability may play a mediating or moderating role in this relationship; however this is not well understood. The objective of this study was to explore cardiac autonomic function and cardiac arrhythmia in depression, the correlation between depression severity and Heart Rate Variability (HRV) related indices, and the prevalence of arrhythmia.

Methods:
Individuals (n = 53) with major depression as assessed by the Diagnostic and Statistical Manual of Mental Disorders, who had a Hamilton Rating Scale for Depression (HAMD) score ≥20 and a Zung Self-Rating Depression Scale score > 53 were compared to 53 healthy individuals, matched for age and gender. Multichannel Electrocardiograph ECG-92C data were collected over 24 hours. Long-term changes in HRV were used to assess the following vagally mediated changes in autonomic tone, expressed as time domain indices: Standard deviation of the NN intervals (SDNN), standard deviation of 5 min averaged NN intervals (SDANN), Root Mean Square of the Successive Differences (RMSSD) and percentage of NN intervals > 50 ms different from preceding interval (pNN50). Pearson’s correlations were conducted to explore the strength of the association between depression severity (using the SDS and HRV related indices, specifically SDNN and low frequency domain / high frequency domain (LF/HF)).

Results:
The values of SDNN, SDANN, RMSSD, PNN50 and HF were lower in the depression group compared to the control group (P<.05). The mean value of the LF in the depression group was higher than the in control group (P<.05). Furthermore the ratio of LF/HF was higher among the depression group than the control group (P<.05). A linear relationship was shown to exist between the severity of the depression and HRV indices. In the depression group, the prevalence of arrhythmia was significantly higher than in the control group (P<.05), particularly supraventricular arrhythmias.

Conclusions:
Our findings suggest that depression is accompanied by dysfunction of the cardiac autonomic nervous system, and further, that depression severity is linked to severity of this dysfunction. Individuals with depression appear to be susceptible to premature atrial and/or ventricular disease.

Methylmercury-induced inhibition of paraoxonase-1 (PON1)-implications for cardiovascular risk

Methylmercury (MeHg) has been associated with increased risk for cardiovascular disease in some but not all epidemiology studies. These inconsistent results may stem from the fact that exposure typically occurs in the context of fish consumption, which is also associated with cardioprotective factors such as omega-3 fatty acids. Mechanistic information may help to understand whether MeHg represents a risk to cardiovascular health. MeHg is a pro-oxidant that inactivates protein sulfhydryls. These biochemical effects may diminish critical antioxidant defense mechanism(s) involved in protecting against atherosclerosis. One such defense mechanism is paraoxonase-1 (PON1), an enzyme present on high-density lipoproteins and that prevents the oxidation of blood lipids and their deposition in vascular endothelium. PON1 is potentially useful as a clinical biomarker of cardiovascular risk, as well as a critical enzyme in the detoxification of certain organophosphate oxons. MeHg and other metals are known to inhibit PON1 activity in vitro. MeHg is associated with lowered serum PON1 activity in a fish-eating population. The implications of lowering PON1 are evaluated by predicting the shift in PON1 population distribution induced by various doses of MeHg. An MeHg dose of 0.3 μg/kg/d is estimated to decrease the population average PON1 level by 6.1% and to increase population risk of acute cardiovascular events by 9.7%. This evaluation provides a plausible mechanism for MeHg-induced cardiovascular risk and suggests means to quantify the risk. This case study exemplifies the use of upstream disease biomarkers to evaluate the additive effect of chemical toxicity with background disease processes in assessing human risk.

Platelet supersensitivity to thrombin stimulation in depression: a possible mechanism for the association with cardiovascular mortality.

The mortality risk associated with cardiovascular disease is significantly increased in patients with major depression and panic disorder. The mechanism of this phenomenon is unclear. Thrombin is responsible for platelet aggregation and shape change, and it plays a significant role in the development of thromboembolic events. In this study, we examined the platelet second messenger intracellular calcium response to thrombin stimulation in patients with major depression (n = 13), major depression after response to electroconvulsive therapy (ECT; n = 13), subsyndromal depression (n = 16), schizophrenia (n = 15), and control subjects (n = 65). Patients with major depression had significantly higher intracellular calcium responses to thrombin stimulation than control subjects, patients with subsyndromal depression, and patients with schizophrenia (p < 0.05). Electroconvulsive therapy did not significantly change this supersensitivity. This suggests that the platelet response to activation in patients with major depression is supersensitive. This study suggests a possible mechanism for the increased risk of cardiovascular disease that is seen in these two psychiatric disorders. The lack of difference between the control and subsyndromal depression groups appears to validate current diagnostic thresholds in depression. The failure of nonpharmacologic treatment to alter this marker suggests that it may be a trait marker of depression.