BackgroundHigh sedentary time, low physical activity (PA), and low physical fitness place older adults at increased risk of chronic diseases, functional decline, and premature mortality. Mobile health (mHealth) apps, apps that run on mobile platforms, may help promote active living.ObjectiveWe aimed to quantify the effect of mHealth app interventions on sedentary time, PA, and fitness in older adults.MethodsWe systematically searched five electronic databases for trials investigating the effects of mHealth app interventions on sedentary time, PA, and fitness among community-dwelling older adults aged 55 years and older. We calculated pooled standardized mean differences (SMDs) in these outcomes between the intervention and control groups after the intervention period. We performed a Cochrane risk of bias assessment and Grading of Recommendations, Assessment, Development, and Evaluation certainty assessment.ResultsOverall, six trials (486 participants, 66.7% [324/486] women; age mean 68 [SD 6] years) were included (five of these trials were included in the meta-analysis). mHealth app interventions may be associated with decreases in sedentary time (SMD=−0.49; 95% CI −1.02 to 0.03), increases in PA (506 steps/day; 95% CI −80 to 1092), and increases in fitness (SMD=0.31; 95% CI −0.09 to 0.70) in trials of 3 months or shorter and with increases in PA (753 steps/day; 95% CI −147 to 1652) in trials of 6 months or longer. Risk of bias was low for all but one study. The quality of evidence was moderate for PA and sedentary time and low for fitness.ConclusionsmHealth app interventions have the potential to promote changes in sedentary time and PA over the short term, but the results did not achieve statistical significance, possibly because studies were underpowered by small participant numbers. We highlight a need for larger trials with longer follow-up to clarify if apps deliver sustained clinically important effects.

Objective: This review explored whether cardiorespiratory fitness or physical activity act as either confounders or effect modifiers of the relationship between adiposity markers and all-cause mortality in older adults. Methods: Systematic searches were carried out to identify observational studies that examined the association of adiposity markers (BMI, waist circumference, and waist-hip ratio) with all-cause mortality in adults aged 60 which took into account cardiorespiratory fitness or physical activity. Data from each included study was analyzed to produce a graphical representation of this relationship. Results: Fourteen of the fifteen identified studies found that increasing BMI had a non-positive association with all-cause mortality, with persistence of the obesity paradox despite adjustment for physical activity or cardiorespiratory fitness. Physical activity measurement methods were all subjective and often unvalidated. The two studies stratifying for cardiorespiratory fitness did not find that fitness had a significant impact on the relationship between excess adiposity and mortality but found that overweight and fit people had better survival than normal-weight unfit people, Conclusions: The predominant use of poor physical activity measurement suggests that studies are currently not adequately accounting for possible physical activity confounding. More studies are needed for addressing the modification of the relationship between adiposity markers and mortality by cardiorespiratory fitness.

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Neurocognitive impairment (NCI) remains prevalent in the highly active antiretroviral therapy (HAART) era. Memory function is commonly affected. There is a need for a rapid, but sensitive screening tool. This study compares the Prospective and Retrospective Memory Questionnaire (PRMQ) and a computerised battery cognitive assessment to establish if the questionnaire has potential as a rapid screening tool for HIV-associated NCI. Neurologically asymptomatic patients with an undetectable HIV viral load on stable HAART were eligible to participate. Asymptomatic NCI (aNCI) was defined as a performance score more than 1SD below the normative mean in at least two domains of the computerised test. Memory impairment (MI) was defined as a t-score more than 1 SD below the normative mean using the PRMQ. Forty-five subjects participated. The mean age was 48 years (SD 11), the mean CD4 count was 546 cells/mul (SD 271), and 84% were male. Of subjects, 14/45 (24%) had NCI and 15/45 (33%) had MI. Two subjects had both types of impairment. No significant association was found between the presence of aNCI and MI (p = 0.229, r = 0.18, 95% CI -1.2, 0.23). aNCI was statistically significantly associated with younger age (p = 0.38, r = 0.31, 95% CI -0.02, 0.001). MI was statistically significantly associated with the set-shifting cognitive domain of the computerized battery (p = 0.04, r = 0.326) and time elapsed since HIV diagnosis (p = 0.035, r = 0.316). High rates of asymptomatic NCI were observed in this cohort, especially in younger individuals. The memory questionnaire did not reliably identify HIV-associated NCI other than executive function deficits and based on our data should therefore not be used as a rapid screening tool for this purpose.