Despite convincing evidence that management of cardiovascular risk factors can reduce morbidity and mortality in patients with Type 2 diabetes, we found that cardiovascular risk is treated less aggressively in patients with both Type 2 diabetes and serious mental illnesses compared with nonmentally ill patients with Type 2 diabetes. Specifically, we found that less than one quarter of diabetes patients with schizophrenia and mood disorders were prescribed lipid-lowering statins and angiotensin-blocking medications compared with approximately half of diabetes patients without SMI. Recent large population-based studies of diabetes (Nau et al., 2004
; Nau and Mallya 2005
; Safford et al., 2003
; Timpe et al., 2004
) show the frequency of use of both cholesterol-lowering medications (approximately 40%) and ACEIs/ARBs (approximately 50%) to be generally comparable to that which we observed in our nonmentally ill sample with diabetes.
Although the rationale for treatment with both statins and ACEIs/ARBs is the attenuation of cardiovascular risk, emerging evidence suggests that cardiovascular events are reduced by these agents regardless of lipid levels or the presence of hypertension (Colhoun et al., 2004
; Collins et al., 2003
; Kurtz and Pravenec, 2004
). Therefore, although the benefits of such treatments might be greatest in diabetes patients with more risk factors for CVD, current evidence suggests that extent of cardiovascular risk need not factor heavily into the prescribing decision. However, if clinicians’ prescribing choices were based on patients’ cardiovascular risk profiles, we would have expected patients with both diabetes and SMI to have fewer cardiovascular risk factors than those without SMI and diabetes, a hypothesis that was not realized in this study.
In contrast, we found that few diabetes patients, both with and without SMI, are achieving target goals for cholesterol and blood pressure recommended by the ADA. Our observations are consistent with other population-based (Kerr et al., 2004
; Saydah et al., 2004
) and clinic-based studies (Grant et al., 2005
; Kennedy et al., 2005
; Wexler et al., 2005
) of the general population with Type 2 diabetes. Second, we found that similar and substantial numbers of diabetes patients with and without SMI in this study met criteria for the metabolic syndrome, a cluster of risk factors including elevated cholesterol and blood pressure along with obesity and hyperglycemia that has been associated with increased mortality overall and from CVD in men and heightened risk of CVD in women (Lakka et al., 2002
). A third important consideration is that more diabetes patients with SMI smoked and were prescribed antipsychotics and other psychotropic medications with known metabolic adverse effects. These findings suggest that many diabetes patients with SMI may be at very high risk for cardiovascular events according to a recent classification established by the NCEP (Grundy et al., 2004
). Very high-risk patients are those who have established CVD together with multiple risk factors (e.g., diabetes), severe and poorly controlled risk factors (e.g., smoking), or the metabolic syndrome, or who are hospitalized for acute coronary syndromes. Even more aggressive LDL lowering (<70 mg/dl) than that suggested by the ADA (<100 mg/dl) is recommended in these patients, but is unlikely to be achieved given the infrequent use of cholesterol-lowering medications that we observed in diabetes patients with SMI in our study.
Our data do not support the notion that inadequate management of cardiovascular risk in diabetes patients with SMI results from a lack of access to medical care services. Diabetes patients both with and without SMI had similar numbers of hospitalizations and outpatient visits related to diabetes over the preceding 6 months in our study. This finding is consistent with our previous work (Dickerson et al., 2003
) and the work of Druss and Rosenheck (1998)
, who observed that patients with mental illnesses make relatively frequent use of general medical services.
Even if access to treatment is equitable for diabetes patients with SMI, our results suggest there are disparities with respect to the quality and appropriateness of diabetes care provided to these patients. Previous work provides support for this hypothesis, although the data are not completely consistent. For example, in a study of patients receiving care at VA centers, Druss et al. (2002)
observed that patients with mental disorders, and particularly those with substance use diagnoses, were less likely to receive recommended preventive services (e.g., immunization and cancer screenings) than patients without psychiatric conditions. Similarly, Druss et al. (2000)
found that patients with psychiatric disorders were less likely than patients without these conditions to receive specialized cardiac procedures following hospitalization for acute myocardial infarction in nongovernmental acute care facilities. However, a comparable study conducted in the VA revealed that patients with mental illnesses were equally as likely as other patients to receive cardiac revascularization procedures or beneficial medications (e.g., thrombolytic therapy, β
-blockers, ACEIs, aspirin) following acute myocardial infarction (Petersen et al., 2003
). More work is needed to understand if and how the quality of care for persons with SMI is deficient, as well as the role of particular care systems (e.g., VA) in reducing or exacerbating potential quality problems.
Other possible explanations for the observed disparities include clinicians’ hesitance to prescribe additional medications to patients who may have difficulty adhering to complex treatment regimens. It may also be that patients’ mental health needs take precedence over their medical needs or that there is an overemphasis on short-term diabetes outcomes such as controlling blood glucose that overshadow more long-term treatment goals such as reducing cardiovascular risk. We were not able to examine these possible explanations in the current study, but further investigation is warranted. The next steps in research in this area should also address some of the limitations of our study, including a relatively small sample size that precluded any efforts to examine the influence of antipsychotic medications or treatment setting on extent and management of cardiovascular risk. Further, we did not investigate whether any of the diabetes patients in our study possessed contraindications to treatment with statins or ACEIs/ARBs such as drug-drug or drug-disease interactions, although we know of no significant interactions between these agents and the primary treatments for schizophrenia or major mood disorders.