Heart rate variability and fasting plasma glucose as trait marker of psychosis: A comparative study between drug naive patients with psychosis and healthy volunteers

BACKGROUND: To date, mixed results have been obtained regarding the metabolic and cardiovascular changes in drug-naïve psychotic patients. Moreover, very few Indian studies are available on this subject. The current study adds to the Indian research on metabolic and cardiovascular factors associated with psychotic disorders. AIM: The aim of the study is to determine that metabolic abnormalities such as “impaired glucose tolerance, abnormal lipid profile, and cardiovascular risks are associated with the pathophysiology of the disease itself, i.e., psychosis. MATERIALS AND METHODS: The present study was a hospital-based cross-sectional study conducted over 2 years that included 30 drug-naïve psychotic patients as per ICD-10 DCR and 20 healthy volunteers. Purposive sampling was done. The patients and matched healthy volunteers fulfilling the inclusion and exclusion criteria were assessed to obtain the sociodemographic data, and a mental state examination was done. Positive and Negative Syndrome Scale was applied to patients only. The required investigations, such as lipid profile, sugar profile, body mass index, and electrocardiogram (ECG) for root mean square standard deviation (RMSSD) (heart rate variability [HRV]-time domain), heart rate, and corrected QT interval, were done in both the groups after obtaining written informed consent. The ECGs of all subjects in both groups were obtained mostly in the morning between 10 am and 12 am. The subjects were asked to avoid coffee and nicotine for 1 h before the ECG recording. The patient was asked to rest for 10 min before the recording and 1 min 6-lead ECG recording was obtained in a supine position at complete rest. RMSSD was calculated from the reading of lead II on 1 min resting ECG. RESULTS: Most of the metabolic and cardiovascular factors showed no statistically significant difference between the two groups except fasting blood sugar (FBS) ( t = 0.843, P = 0.033), and median value of HRV ( P = 0.008). Mean FBS was higher in the patient group compared to the control, and mean HRV was lower in the patient group compared to the control. CONCLUSION: The findings of the current study, in conjunction with the findings from other methodologically similar studies, suggest that lower HRV and abnormal fasting glucose may be associated with the psychopathology of psychotic illnesses.