The associations of resting metabolic rate with chronic conditions and weight loss.

The aim of this study was to examine the associations between baseline and changes in resting metabolic rate (RMR) with chronic condition(s) and weight loss (WL). Sex stratified analysis was undertaken on 393 adults from the Wharton Weight Management Clinics. The association between baseline RMR and WL was examined adjusting for age, BMI, ethnicity and treatment time. The association between changes in RMR (ΔRMR) and WL was also examined adjusting for baseline RMR and above covariates. Models were further adjusted for high glucose, triglycerides, blood pressure, low-density lipoprotein (LDL) and low high-density lipoprotein (HDL). While men (6.0 ± 8.6 kg) and women (5.6 ± 8.3 kg) had significant WL throughout the intervention, their measured decreases in RMR (-48 ± 322 kcal and -5 ± 322 kcal, respectively) were non-significant (P > 0.05). Individuals with a high blood pressure had a higher baseline RMR and women with a high LDL had a lower baseline RMR than those without the chronic condition (P < 0.05). Regardless of sex, WL was not significantly associated with baseline RMR or ΔRMR (P > 0.05) in both models. Participants with a low baseline RMR do not appear to be at a disadvantage for WL. Further, WL can occur without decreases in RMR in populations with high levels of obesity and obesity-related comorbidities.

Tricyclic and SSRI usage influences the association between BMI and health risk factors.

To determine if selective-serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) influence the association between obesity and cardiovascular disease risk, participants from the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1992) and continuous NHANES (1999-2009, n = 18 274) were used. For a given body mass index (BMI), individuals taking SSRIs (n = 219) tended to have significantly better health risk profiles with lower systolic blood pressure (P = 0.002) and higher high-density lipoprotein (P = 0.003) compared with non-users. Conversely, those who used TCAs (n = 116) had significantly worse health risk profiles with higher diastolic blood pressure (P ≤ 0.0001) and triglycerides (P = 0.023) as compared with non-users for a given BMI. Insulin resistance (HOMA-IR) was higher in TCA users and those with larger BMIs, whereby the differences in insulin resistance between TCA users and non-users was greater with higher BMIs (interaction effect: P = 0.013). Furthermore, individuals taking SSRIs were less likely to have cardiovascular disease than non-users (odds ratio, 95% confidence interval = 0.50, 0.33-0.75) for a given BMI, with no differences by TCA use (odds ratio = 0.74, 0.44-1.24). SSRI and TCA use may alter how body weight relates with cardiovascular risk. When prescribing antidepressant medications, it may be necessary to monitor and consider body weight and cardiovascular risk profile of individual patients.