23.6 million (8%) of the U.S. population have diabetes (National Diabetes Information Clearing House, 2007
). Diabetic patients are twice as likely to have depression compared with matched controls without diabetes (Lin et al., 2004
). Furthermore, depressive symptoms are more common in individuals with diabetes than in those without (Golden et al., 2008
). The impact of exercise on diabetes (Morrato, Hill, Wyatt, Ghushchyan, & Sullivan, 2007
), depression (Penninx et al., 2002
), and resistance exercise training with depression (Singh, Clements, & Fiatarone, 1997
) has been documented.
Much of the research on Hispanics in the United States has failed to take into account important intragroup variation. However, the prevalence of type 2 diabetes among elderly participants in the United States, South America, and the Caribbean varies by Hispanic subgroups. Specifically, Puerto Ricans have significantly higher rates of diabetes (38%) than non-Hispanic Whites (23%; Tucker, Bermudez, & Castaneda, 2000
). Depression and diabetes co-occur more frequently among older Hispanic/Latinos than in other populations; however, Hispanics are less likely than non-Hispanic Whites to be diagnosed and half as likely to receive treatment for depression (Cherrington, Ayala, Sleath, & Corbie-Smith, 2006
Lack of exercise is an important risk factor for both depression (Barbour & Blumenthal, 2005
) and diabetes (Golden et al., 2008
; Lin et al., 2004
; Morrato et al., 2007
). Although a number of intervention studies have been conducted to examine the benefits of exercise in patients with diabetes (Morrato et al., 2007
), few have focused on older adults (Castaneda et al., 2002
) and even fewer have targeted Hispanics (Castaneda et al., 2002
). A randomized controlled trial of high-intensity progressive resistance exercise training (PRT) performed for 16 weeks with 58 Hispanic older adults with poorly controlled type 2 diabetes found that this exercise modality significantly improved glycemic control and diabetes management compared with a control group who did not undergo exercise training (Castaneda et al., 2002
). The authors found that not only did PRT improved glycemic control and insulin sensitivity, but it also increased fat-free mass, reduced the requirement for diabetes medications, reduced abdominal adiposity and systolic blood pressure, and increased muscle strength and spontaneous physical activity.
Other research has examined the impact of exercise interventions in people with depression. Aerobic exercise training (Penninx et al., 2002
) and resistance exercise training (Singh et al. 1997
) are as effective as antidepressants thus are recommended as an alternative to antidepressants. Furthermore, a long-term follow-up found that these positive lifestyle changes were maintained by participants. Therefore, exercise proves not only physically but also psychologically beneficial and should be considered a part of routine treatment for depression.
We have found no studies examining the impact of resistance exercise training on depression among people with type 2 diabetes. Therefore, we examined the hypothesis that an intervention designed to improve glycemic/metabolic control has the additional benefit of improving mental health among Puerto Rican elders with type 2 diabetes. We used data gathered in a randomized control trial (RCT) on resistance exercise training and type 2 diabetes to examine the impact on mental health outcomes.