Effects of depression, metabolic syndrome, and cardiorespiratory fitness on mortality: results from the Cooper Center Longitudinal Study.

BACKGROUND: Depression and metabolic syndrome (MetS) are frequently comorbid disorders that are independently associated with premature mortality. Conversely, cardiorespiratory fitness (CRF) is associated with reduced mortality risk. These factors may interact to impact mortality; however, their effects have not been assessed concurrently. This analysis assessed the mortality risk of comorbid depression/MetS and the effect of CRF on mortality in those with depression/MetS. METHODS: Prospective study of 47 702 adults in the Cooper Center Longitudinal Study. Mortality status was attained from the National Death Index. History of depression was determined by patient response (yes or no) to a standardized medical history questionnaire. MetS was categorized using the American Heart Association/National Heart, Lung, and Blood Institute criteria. CRF was estimated from the final speed/grade of a treadmill graded exercise test. RESULTS: 13.9% reported a history of depression, 21.4% met criteria for MetS, and 3.0% met criteria for both MetS and history of depression. History of depression (HR = 1.24, p = 0.003) and MetS (HR = 1.28, p < 0.001) were independently associated with an increased mortality risk, with the greatest mortality risk among individuals with both a history of depression and MetS (HR = 1.59, p < 0.001). Higher CRF was associated with a significantly lower risk of mortality (p < 0.001) in all individuals, including those with MetS and/or a history of depression. CONCLUSIONS: Those with higher levels CRF had reduced mortality risk in the context of depression/MetS. Interventions that improve CRF could have substantial impact on the health of persons with depression/MetS.

Racial and ethnic differences in treatment outcomes among adults with stimulant use disorders after a dosed exercise intervention.

The current study examined differences in substance abuse treatment outcomes among racial and ethnic groups enrolled in the Stimulant Reduction Intervention using Dosed Exercise (STRIDE) trial, a multisite randomized clinical trial implemented through the National Institute on Drug Abuse's (NIDA's) Clinical Trials Network (CTN). STRIDE aimed to test vigorous exercise as a novel approach to the treatment of stimulant abuse compared to a health education intervention. A hurdle model with a complier average causal effects (CACE) adjustment was used to provide an unbiased estimate of the exercise effect had all participants been adherent to exercise. Among 214 exercise-adherent participants, we found significantly lower probability of use for Blacks (z = -2.45, p = .014) and significantly lower number of days of use for Whites compared to Hispanics (z = -54.87, p = <.001) and for Whites compared to Blacks (z = -28.54, p = <.001), which suggests that vigorous, regular exercise might improve treatment outcomes given adequate levels of adherence.

Pro-inflammatory cytokines as predictors of antidepressant effects of exercise in major depressive disorder.

Exercise is an efficacious treatment for major depressive disorder (MDD) and has independently been shown to have anti-inflammatory effects in non-depressed subjects. Patients with MDD have elevated inflammatory cytokines but it is not known if exercise affects inflammation in MDD patients and whether these changes are clinically relevant. In the TReatment with Exercise Augmentation for Depression (TREAD) study, participants who were partial responders to a selective serotonin reuptake inhibitor were randomized to receive one of two doses of exercise: 16 kilocalories per kilogram of body weight per week (KKW), or 4 KKW for 12 weeks. Blood samples were collected before initiation and again at the end of the 12-week exercise intervention. Serum was analyzed using a multiplexed ELISA for interferon-γ (IFN-γ), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Higher baseline levels of TNF-α were associated with greater decrease in depression symptoms over the 12-week exercise period (P<0.0001). In addition, a significant positive correlation between change in IL-1ß and change in depression symptom scores was observed (P=0.04). There were no significant changes in mean level of any cytokine following the 12-week intervention, and no significant relationship between exercise dose and change in mean cytokine level. Results suggest that high TNF-α may differentially predict better outcomes with exercise treatment as opposed to antidepressant medications for which high TNF-α is linked to poor response. Our results also confirm findings from studies of antidepressant medications that tie decreasing IL-1ß to positive depression treatment outcomes.

Does exercise improve self-reported sleep quality in non-remitted major depressive disorder?

BACKGROUND: Sleep disturbances are persistent residual symptoms following remission of major depressive disorder (MDD) and are associated with an increased risk of MDD recurrence. The purpose of the current study was to examine the effect of exercise augmentation on self-reported sleep quality in participants with non-remitted MDD. Method Participants were randomized to receive selective serotonin reuptake inhibitor (SSRI) augmentation with one of two doses of exercise: 16 kilocalories per kilogram of body weight per week (KKW) or 4 KKW for 12 weeks. Depressive symptoms were assessed using the clinician-rated Inventory of Depressive Symptomatology (IDS-C). The four sleep-related items on the IDS-C (Sleep Onset Insomnia, Mid-Nocturnal Insomnia, Early Morning Insomnia, and Hypersomnia) were used to assess self-reported sleep quality. RESULTS: Significant decreases in total insomnia (p < 0.0001) were observed, along with decreases in sleep onset, mid-nocturnal and early-morning insomnia (p's <0.002). Hypersomnia did not change significantly (p = 0.38). Changes in total, mid-nocturnal and early-morning insomnia were independent of changes in depressive symptoms. Higher baseline hypersomnia predicted a greater decrease in depression severity following exercise treatment (p = 0.0057). No significant moderating effect of any baseline sleep on change in depression severity was observed. There were no significant differences between exercise treatment groups on total insomnia or any individual sleep item. CONCLUSIONS: Exercise augmentation resulted in improvements in self-reported sleep quality in patients with non-remitted MDD. Given the prevalence of insomnia as a residual symptom following MDD treatment and the associated risk of MDD recurrence, exercise augmentation may have an important role in the treatment of MDD.

Gender and racial/ethnic differences in physiologic responses in the Stimulant Reduction Intervention using Dosed Exercise Study.

Exercise may be beneficial for individuals in substance use disorder (SUD) treatment given the higher rates of both medical and psychiatric comorbidity, namely mood and anxiety disorders, compared to the general population. Gender and/or racial/ethnic differences in health benefits and response to prescribed exercise have been reported and may have implications for designing exercise interventions in SUD programs. METHOD: Data are from the National Drug Abuse Treatment Clinical Trials Network (NIDA/CTN) Stimulant Reduction Intervention using Dosed Exercise (STRIDE) trial. Gender differences across racial/ethnic groups in physiological responses and stimulant withdrawal severity across time were analyzed using linear mixed effects models. RESULTS: Males completed significantly more exercise sessions than females and were more adherent to the prescribed exercise dose of 12 Kcal/Kg/Week. Controlling for age, race/ethnicity, treatment group and stimulant withdrawal severity, there was a significant gender by time interaction for body mass index (BMI) (p < 0.001), waist circumference (p < 0.001) and heart rate measured prior to exercise sessions (p < 0.01). For females, body mass index (BMI) and waist circumference increased over time while for males BMI and waist circumference stayed unchanged or slightly decreased with time. Heart rate over time significantly increased for females at a higher rate than in males. Stimulant withdrawal severity was similar in males and females at baseline but males exhibited a significant decrease over time while females did not. Although baseline differences were observed, there were no time by race/ethnicity differences in physiologic responses. DISCUSSION: Gender differences in response to exercise may have implications for developing gender specific exercise interventions in SUD programs.

IL-1ß and BDNF are associated with improvement in hypersomnia but not insomnia following exercise in major depressive disorder.

Given the role of sleep in the development and treatment of major depressive disorder (MDD), it is becoming increasingly clear that elucidation of the biological mechanisms underlying sleep disturbances in MDD is crucial to improve treatment outcomes. Sleep disturbances are varied and can present as insomnia and/or hypersomnia. Though research has examined the biological underpinnings of insomnia in MDD, little is known about the role of biomarkers in hypersomnia associated with MDD. This paper examines biomarkers associated with changes in hypersomnia and insomnia and as predictors of improvements in sleep quality following exercise augmentation in persons with MDD. Subjects with non-remitted MDD were randomized to augmentation with one of two doses of aerobic exercise: 16 kilocalories per kilogram of body weight per week (KKW) or 4 KKW for 12 weeks. The four sleep-related items on the clinician-rated Inventory of Depressive Symptomatology (sleep onset insomnia, mid-nocturnal insomnia, early morning insomnia and hypersomnia) assessed self-reported sleep quality. Inflammatory cytokines (tumor necrosis factor-alpha, interleukin (IL)-1ß, IL-6) and brain-derived neurotrophic factor (BDNF) were assessed in blood samples collected before and following the 12-week intervention. Reduction in hypersomnia was correlated with reductions in BDNF (ρ = 0.26, P = 0.029) and IL-1ß (ρ = 0.37, P = 0.002). Changes in these biomarkers were not associated with changes in insomnia; however, lower baseline levels of IL-1ß were predictive of greater improvements in insomnia (F = 3.87, P = 0.050). In conclusion, improvement in hypersomnia is related to reductions in inflammatory markers and BDNF in persons with non-remitted MDD. Distinct biological mechanisms may explain reductions in insomnia.