Objective: To examine the effect of a lifestyle behavior intervention (SystemCHANGE) on physical activity and diet quality among sedentary people living with HIV (PLHIV). All participants expressed a desire to improve lifestyle health behaviors. Methods: One hundred and seven HIV+ adults were randomized to either the intervention (6, in-person, standardized group sessions focusing on improving lifestyle behaviors) or a control condition (general advice on AHA diet and exercise guidelines). All participants wore an ActiGraph accelerometer and completed 24-hour dietary recalls at baseline, 3, and 6 months. Generalized estimating equations were used to examine intervention effects. The primary activity outcome was time spent in moderate-to-vigorous physical activity, and the primary dietary outcome was Healthy Eating Index. Results: Mean age was 53 years, 65% were male, and 86% African American. Approximately 90% attended at least half of the sessions and 60% attended 5 or more sessions. The intervention did not significantly improve our primary lifestyle behavior endpoints (P ≥ 0.05); however, intervention participants consumed fewer carbohydrates—primarily sugar-sweetened beverages—per day and lost 0.732 kg body weight compared with a 0.153 weight gain in the control group (P = 0.03). Conclusions: Among sedentary PLHIV at high risk of cardiovascular disease, the SystemCHANGE intervention reduced daily carbohydrate intake and body weight, but did not increase physical activity or improve overall diet quality. Future work should identify fundamental personal, interpersonal, and contextual factors that will increase physical activity and improve overall diet quality among this population, and integrate these factors into tailored, lifestyle interventions for aging PLHIV.

The zebrafish (Danio rerio) has been used as a model for studying vertebrate development in the cardiovascular system. In order to monitor heart contraction and cytosolic calcium oscillations, fish were either embedded in methylcellulose or anesthetized with tricaine. Using high-resolution differential interference contrast and calcium imaging microscopy, we here show that dopamine and verapamil alter calcium signaling and muscle contraction in anesthetized zebrafish, but not in embedded zebrafish. In anesthetized fish, dopamine increases the amplitude of cytosolic calcium oscillation with a subsequent increase in heart contraction, whereas verapamil decreases the frequency of calcium oscillation and heart rate. Interestingly, verapamil also increases myocardial contraction. Our data further indicate that verapamil can increase myocardial calcium sensitivity in anesthetized fish. Taken together, our data reinforce in vivo cardiac responses to dopamine and verapamil. Furthermore, effects of dopamine and verapamil on myocardial calcium and contraction are greater in anesthetized than embedded fish. We suggest that while the zebrafish is an excellent model for a cardiovascular imaging study, the cardio-pharmacological profiles are very different between anesthetized and embedded fish.