Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries.

BACKGROUND: The prevalence of type 2 diabetes is increased in individuals with mental disorders. Much of the burden of disease falls on the populations of low- and middle-income countries (LMICs). OBJECTIVES: To assess the effects of pharmacological, behaviour change, and organisational interventions versus active and non-active comparators in the prevention or delay of type 2 diabetes among people with mental illness in LMICs. SEARCH METHODS: We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase and six other databases, as well as three international trials registries. We also searched conference proceedings and checked the reference lists of relevant systematic reviews. Searches are current up to 20 February 2020. SELECTION CRITERIA: Randomized controlled trials (RCTs) of pharmacological, behavioural or organisational interventions targeting the prevention or delay of type 2 diabetes in adults with mental disorders in LMICs. DATA COLLECTION AND ANALYSIS: Pairs of review authors working independently performed data extraction and risk of bias assessments. We conducted meta-analyses using random-effects models. MAIN RESULTS: One hospital-based RCT with 150 participants (99 participants with schizophrenia) addressed our review's primary outcome of prevention or delay of type 2 diabetes onset. Low-certainty evidence from this study did not show a difference between atypical and typical antipsychotics in the development of diabetes at six weeks (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.03 to 7.05) (among a total 99 participants with schizophrenia, 68 were in atypical and 31 were in typical antipsychotic groups; 55 participants without mental illness were not considered in the analysis). An additional 29 RCTs with 2481 participants assessed one or more of the review's secondary outcomes. All studies were conducted in hospital settings and reported on pharmacological interventions. One study, which we could not include in our meta-analysis, included an intervention with pharmacological and behaviour change components. We identified no studies of organisational interventions. Low- to moderate-certainty evidence suggests there may be no difference between the use of atypical and typical antipsychotics for the outcomes of drop-outs from care (RR 1.31, 95% CI 0.63 to 2.69; two studies with 144 participants), and fasting blood glucose levels (mean difference (MD) 0.05 lower, 95% CI 0.10 to 0.00; two studies with 211 participants). Participants who receive typical antipsychotics may have a lower body mass index (BMI) at follow-up than participants who receive atypical antipsychotics (MD 0.57, 95% CI 0.33 to 0.81; two studies with 141 participants; moderate certainty of evidence), and may have lower total cholesterol levels eight weeks after starting treatment (MD 0.35, 95% CI 0.27 to 0.43; one study with 112 participants). There was moderate certainty evidence suggesting no difference between the use of metformin and placebo for the outcomes of drop-outs from care (RR 1.22, 95% CI 0.09 to 16.35; three studies with 158 participants). There was moderate-to-high certainty evidence of no difference between metformin and placebo for fasting blood glucose levels (endpoint data: MD -0.35, 95% CI -0.60 to -0.11; change from baseline data: MD 0.01, 95% CI -0.21 to 0.22; five studies with 264 participants). There was high certainty evidence that BMI was lower for participants receiving metformin compared with those receiving a placebo (MD -1.37, 95% CI -2.04 to -0.70; five studies with 264 participants; high certainty of evidence). There was no difference between metformin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Low-certainty evidence from one study (48 participants) suggests there may be no difference between the use of melatonin and placebo for the outcome of drop-outs from care (RR 1.00, 95% CI 0.38 to 2.66). Fasting blood glucose is probably reduced more in participants treated with melatonin compared with placebo (endpoint data: MD -0.17, 95% CI -0.35 to 0.01; change from baseline data: MD -0.24, 95% CI -0.39 to -0.09; three studies with 202 participants, moderate-certainty evidence). There was no difference between melatonin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Very low-certainty evidence from one study (25 participants) suggests that drop-outs may be higher in participants treated with a tricyclic antidepressant (TCA) compared with those receiving a selective serotonin reuptake inhibitor (SSRI) (RR 0.34, 95% CI 0.11 to 1.01). It is uncertain if there is no difference in fasting blood glucose levels between these groups (MD -0.39, 95% CI -0.88 to 0.10; three studies with 141 participants, moderate-certainty evidence). It is uncertain if there is no difference in BMI and depression between the TCA and SSRI antidepressant groups. AUTHORS' CONCLUSIONS: Only one study reported data on our primary outcome of interest, providing low-certainty evidence that there may be no difference in risk between atypical and typical antipsychotics for the outcome of developing type 2 diabetes. We are therefore not able to draw conclusions on the prevention of type 2 diabetes in people with mental disorders in LMICs. For studies reporting on secondary outcomes, there was evidence of risk of bias in the results. There is a need for further studies with participants from LMICs with mental disorders, particularly on behaviour change and on organisational interventions targeting prevention of type 2 diabetes in these populations.

Prevalence of Overweight and Obesity in People With Severe Mental Illness: Systematic Review and Meta-Analysis.

Aims: 1) To determine the pooled prevalence of overweight and obesity in people with severe mental illness (SMI), overall and by type of SMI, geographical region, and year of data collection; and 2) to assess the likelihood of overweight and obesity, in people with SMI compared with the general population. Methods: PubMed, Medline, EMBASE, and PsycINFO databases were searched to identify observational studies assessing the prevalence of obesity in adults with SMI. Screening, data extraction and risk of bias assessments were performed independently by two co-authors. Random effect estimates for the pooled prevalence of overweight and obesity and the pooled odds of obesity in people with SMI compared with the general population were calculated. Subgroup analyses were conducted for types of SMI, setting, antipsychotic medication, region of the world, country income classification, date of data collection and sex. We assessed publication bias and performed a series of sensitivity analyses, excluding studies with high risk of bias, with low sample size and those not reporting obesity according to WHO classification. Result: 120 studies from 43 countries were included, the majority were from high income countries. The pooled prevalence of obesity in people with SMI was 25.9% (95% C.I. = 23.3-29.1) and the combined pooled prevalence of overweight and obesity was 60.1% (95% C.I. = 55.8-63.1). Sub-Saharan Africa (13.0%, 95%C.I. = 6.7-25.1) and South Asia (17.7%, 95%C.I. = 10.5-28.5) had the lowest prevalence of obesity whilst North Africa and the Middle East (35.8%, 95%C.I. = 23.8-44.8) reported the highest prevalence. People with SMI were 3.04 more likely (95% C.I. = 2.42-3.82) to have obesity than the general population, but there was no difference in the prevalence of overweight. Women with schizophrenia were 1.44 (95% C.I. = 1.25-1.67) times more likely than men with schizophrenia to live with obesity; however, no gender differences were found among those with bipolar disorder. Conclusion: People with SMI have a markedly high prevalence and higher odds of obesity than the general population. This may contribute to the very high prevalence of physical health conditions and mortality in this group. People with SMI around the world would likely benefit from interventions to reduce and prevent obesity.