Protecting cardiometabolic health
People with severe mental illnesses, such as schizophrenia and bipolar disease, die 10-20 years earlier on average than the general population. Three-quarters of these premature deaths arise from physical illnesses’ usual suspects. Cardiovascular disease (CVD) is the single biggest cause of premature mortality and much more common than suicide. Reductions in CVD morbidity and mortality seen in the general population over the last two decades have not benefitted people with severe mental illness, for whom CVD and diabetes prevalence is two-three fold greater. The National Audit of Schizophrenia, reporting on over 5000 patients, found that only 29% were adequately screened for cardiometabolic risk within the previous 12 months. While diabetes itself increases CVD risk, there are practical challenges for managing both diabetes and mental illness together. Obesity, inactivity, social deprivation, smoking and inadequate physical healthcare often further exacerbate the risk in those with SMI, perhaps explaining why those with both diabetes and schizophrenia have 50% poorer survival rates than those with diabetes alone. Thus a treatment gap may be contributing to a widening mortality and morbidity gap. A preventive approach towards diabetes and CVD risk, systematically applied from the onset of psychosis and its treatment, can mitigate these health inequalities.
Severe mental illness (SMI) includes schizophrenia, bipolar illness and severe depressive disorder. Schizophrenia and bipolar disorder are psychotic illnesses characterised by episodes of altered perception, thought, mood and behaviour often with associated social impairments affecting daily life. Lifetime prevalence of schizophrenia is about 1%, bipolar disorder slightly commoner. The onset typically occurs in late adolescence or early adulthood. For most the course is intermittent but for many this can lead to a persisting and disabling condition.
Increased risk of diabetes and CVD
People with SMI are exposed to significantly increased cardiometabolic risk, including central obesity, glucose dysregulation and dyslipidaemia, alongside high rates of smoking, physical inactivity and social disadvantage  .
Table 1: Relative risk of potentially modifiable cardiovascular and metabolic risk factors for people with severe mental illness compared with the general population.
|Proportion of those with SMI affected||Relative risk compared with general population|
|Type 2 Diabetes||10-15%||2-3|
|Dyslipidaemia||25-69%||Up to 5 fold|
The precise nature and relative contribution of psychiatric disorder, socio-demographic impact and adverse effects from antipsychotic medicines is debated. Increased intra-abdominal fat and glucose dysregulation may develop even before treatment commences  but what is striking is how weight gain and disturbances of glucose and lipid metabolism accelerate within weeks of commencing treatment , particularly in younger patients. Indeed in most people with drug-naïve first episode psychosis, metabolic abnormalities do not appear higher than a comparable population without psychosis.
Around 10–15% of people taking antipsychotic medication develop type 2 diabetes (two-three times general population rate). Genetic predisposition has long been recognised, Sir Henry Maudsley noting in The Pathology of Mind (1897) “Diabetes often shows itself in families in which insanity prevails”. However, in recent decades, type 2 diabetes rates have risen relative to the general population, itself facing rising trends. Introduction of second generation antipsychotic drugs (also known as atypical antipsychotics) may partly explain although these patients are not immune to influences of poor diet and physical inactivity affecting the general population. Whatever the explanation, people with SMI are experiencing an epidemic of type 2 diabetes. A European study screened a group of people with schizophrenia not known to have diabetes, and found 10% had the disorder and a further 38% were biochemically at high risk with prediabetes; their average age was only 38 years .
Lipid abnormalities are also common in people with SMI, (25–69%). This is linked to and appears quickly after antipsychotic initiation . Typical changes include raised LDL cholesterol and triglycerides, and decreased HDL cholesterol .
Figure 1 [Click to enlarge]. Weight gain with antipsychotic drugs. With thanks to Dr Mario Alvarez-Jimenez for permission to show this graph.The so-called second generation atypical antipsychotic drugs have been introduced over the last 15 years with the hope that they would replace less effective and poorly tolerated first generation typical drugs. However, it has become increasingly clear that no true class difference exists, claims of effectiveness were exaggerated, and that although the newer drugs may cause fewer movement disorders, most are more likely to cause metabolic disturbances including significant weight gain, albeit with some hierarchy between antipsychotics. The greatest weight gain is seen with clozapine and olanzapine. Furthermore, lack of high-quality research and over-reliance on short duration trials involving people with established illness, many already heavier from previous antipsychotic exposure, may have led to 3-4 fold underestimation of weight gain in people exposed to antipsychotics for the first time (Figure 1). 
Some evidence of increased rates of hypertension, not consistently reported, may reflect that some antipsychotics pharmacologically lower blood pressure, confounding factors such as obesity or smoking which tend to elevate blood pressure.
Unhealthy lifestyles interact with psychiatric illness and treatment to escalate risk of obesity, diabetes and CVD. These patients experience discrimination, isolation, very low rates of employment and poverty. A study led by McCreadie, often regarded as definitive, showed that people with SMI lead sedentary lives, eat less fruit and vegetables, are more obese, smoke heavily and often misuse alcohol. This is concurred by a more recent epidemiological study which found their knowledge was lacking with regard to health risk behaviours .
Smoking rates have declined in the general population from 39% (1980) to about 20% (2013) contrasting with unchanging rates of approximately 70% for those with established schizophrenia. Missing out on effective prevention of one of the most potent CVD risks increases the health inequalities gap .
What is to be done?
Despite higher rates of physical co-morbidity and no lesser personal concern, people with SMI are less likely to receive effective and timely healthcare in clinical practice (e.g. drug prescribing, surgical procedures, population screening, dental care and physical health checks) when compared with patients without mental illness. A different emphasis is therefore required to tackle physical disorders much earlier in their evolution. This requires recognition of a group of people at high risk of dying young from CVD and diabetes while still in their twenties and thirties, and at an age not normally considered for active primary or secondary cardiovascular prevention.
Elements required in a shift towards prevention include:
Clinical responsibility. National Institute for Care and Health Excellence (NICE) guideline for psychosis and schizophrenia (CG 178) recommends:
- The secondary care team should maintain responsibility for monitoring physical health and the effects of antipsychotic medication for at least the first 12 months or until the person’s condition has stabilised, whichever is longer (NICE Recommendation 220.127.116.11)
- GPs and other primary healthcare professionals should monitor physical health from 12 months and then at least once a year. (NICE Recommendation 18.104.22.168)
Effective screening. The Lester Positive Cardiometabolic Health Resource 2014 update offers a framework for preventing, monitoring and intervening early and rapidly when cardiometabolic risks appear. Attention to weight gain, and encouraging healthier diets and physical activity should be routine and available from the start of treatment as shown in the table extracted from the Lester resource:
[Click to enlarge]The new JBS3 lifetime risk calculator is a welcome improvement to risk scoring because it displaces the false reassurance of a low 10-year risk of a CVD event for this younger population by acknowledging their high lifetime event risk and the need for an active prevention approach from the onset of psychosis and its treatment.
For those identified by screening to be at high risk of diabetes, NICE (PH 38) recommends intensive lifestyle interventions; if lifestyle approaches fail, then metformin may also be considered.
Antipsychotic Prescribing. Clear and consistent information should be provided to help patients understand and weigh the benefits and risks of antipsychotic medication, emphasising the trade-offs of improved mental health symptoms versus increased risks to physical health.
Antipsychotic medication should be carefully monitored. If, following treatment initiation, there is rapid (e.g., within three months) weight gain (5kg or more) or if abnormal glucose, lipids or blood pressure develop, a treatment review by the psychiatrist should be triggered promptly. Switching antipsychotics can be effective, although decisions must always be balanced by considerations of the patient’s psychiatric condition.
Lifestyle and life skills. Provide consistent messages to encourage healthier lifestyles and evidence-based support for smoking cessation, and diet and exercise programmes should be available. The impact of key social determinants should not be overlooked on practical issues, such as inadequate housing, lack of access to affordable physical activity, poor cooking skills and limited budget for food.
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