OBJECTIVE: This study aimed to investigate the validity of HR measures of a high-cost consumer-based tracker (Polar A370) and a low-cost tracker (Tempo HR) in the laboratory and free-living settings.
METHODS: Participants underwent a laboratory-based cycling protocol while wearing the two trackers and the chest-strapped Polar H10, which acted as criterion. Participants also wore the devices throughout the waking hours of the following day during which they were required to conduct at least one 10-min bout of moderate-to-vigorous physical activity (MVPA) to ensure variability in the HR signal. We extracted 10-second values from all devices and time-matched HR data from the trackers with those from the Polar H10. We calculated intraclass correlation coefficients (ICCs), mean absolute errors, and mean absolute percentage errors (MAPEs) between the criterion and the trackers. We constructed decile plots that compared HR data from Tempo HR and Polar A370 with criterion measures across intensity deciles. We investigated how many HR data points within the MVPA zone (≥64% of maximum HR) were detected by the trackers.
RESULTS: Of the 57 people screened, 55 joined the study (mean age 30.5 [SD 9.8] years). Tempo HR showed moderate agreement and large errors (laboratory: ICC 0.51 and MAPE 13.00%; free-living: ICC 0.71 and MAPE 10.20%). Polar A370 showed moderate-to-strong agreement and small errors (laboratory: ICC 0.73 and MAPE 6.40%; free-living: ICC 0.83 and MAPE 7.10%). Decile plots indicated increasing differences between Tempo HR and the criterion as HRs increased. Such trend was less pronounced when considering the Polar A370 HR data. Tempo HR identified 62.13% (1872/3013) and 54.27% (5717/10,535) of all MVPA time points in the laboratory phase and free-living phase, respectively. Polar A370 detected 81.09% (2273/2803) and 83.55% (9323/11,158) of all MVPA time points in the laboratory phase and free-living phase, respectively.
CONCLUSIONS: HR data from the examined wrist-worn trackers were reasonably accurate in both the settings, with the Polar A370 showing stronger agreement with the Polar H10 and smaller errors. Inaccuracies increased with increasing HRs; this was pronounced for Tempo HR.
METHODS: In this cross-sectional study among 570 YMSM aged 18 to 25 years old, latent class analysis (LCA) conducted to identify classes with similar patterns of sexualized substance use, across which measures of inconsistent condom use, recent STI diagnoses, past suicide ideation and depression severity were compared.
RESULTS: LCA revealed three classes of YMSM based on types of substances ever used in sexualized contexts, which we labelled as 'substance-naive', 'substance-novice', and 'chemsex'. Substance-naive participants (n = 404) had only ever used alcohol, while substance-novice participants (n = 143) were primarily amyl nitrite users with a small proportion who reported using chemsex-related drugs. Chemsex participants (n = 23) comprised individuals who had mostly used such drugs. Those in the chemsex group were more likely to report recent unprotected anal sex with casual partners (aPR = 3.28, 95%CI [1.85, 5.79]), depression severity (aβ = 3.69, 95%CI [0.87, 6.51]) and a history of suicide ideation (aPR = 1.64, 95%CI [1.33, 2.03]).
CONCLUSIONS: Findings of this study highlight how the use of varying substances in sexualized contexts may be classified and characterized by different sexual and mental health outcomes. Health promotion efforts should be differentiated accordingly to address the risks associated with sexualized substance use among YMSM.
RESULTS: Our findings revealed that uncoated alginate microcapsules ruptured upon drying and exhibited low encapsulation efficiency (13.81 ± 2.76%). However, the addition of chitosan successfully provided a more complex and rigid external wall structure to enhance the stability of the microcapsules. By prolonging the crosslinking time from 5 to 30 min and increasing the chitosan concentration from 0.1% to 0.5%, the oil encapsulation efficiency was increased by 28%. Under the right gelation pH (pH 4), the extension of gelation time from 1 to 12 h resulted in an increase in alginate-Ca2+ crosslinkings, thus strengthening the microcapsules.
CONCLUSION: With the optimum formulation and process parameters, a high encapsulation efficiency (81.49 ± 1.75%) with an elevated oil loading efficiency (63.58 ± 2.96%) were achieved. The final product is biocompatible and can potentially be used for the delivery of palm tocotrienols. © 2021 Society of Chemical Industry.
METHODS: Results of this study were derived from baseline data of the Pink Carpet Y Cohort Study in Singapore, comprising a sample of 570 HIV-negative YMSM aged 18 to 25 years old. Latent class analysis was employed to identify classes with similar patterns of sexualized substance use, and multinomial logistic regression was employed to examine associations between class membership and proxy measures of social capital, including age of sexual debut, bonding and bridging social capital, connectedness to the lesbian, gay, bisexual and transgender community, and outness.
RESULTS: Latent class analysis revealed three classes of YMSM based on their histories of sexualized substance use, which we labelled as 'alcohol', 'poppers', and 'chemsex'. Multivariable analyses revealed that participants who were older (aOR = 1.19, p = 0.002) and who identified as gay (aOR = 2.43, p = 0.002) were more likely to be in the poppers class compared to the alcohol class. Participants with a later age of sexual debut were increasingly less likely to be in the poppers (aOR = 0.93, p = 0.039) and chemsex classes (aOR = 0.85, p = 0.018), compared to the alcohol class.
CONCLUSIONS: Varying measures of social capital such as an earlier age of exposure to sexual networks may predispose YMSM to greater opportunities for sexualized substance use. Future interventions should target YMSM who become sexually active at an earlier age to reduce the risks associated with sexualized substance use.