Objective and subjective sleep measures are associated with HbA1c and insulin sensitivity in the general population: Findings from the ORISCAV-LUX-2 study.

AIM: To analyze the association of objective and subjective sleep measures with HbA1c and insulin sensitivity in the general population. METHODS: Using a cross-sectional design, data from 1028 participants in the ORISCAV-LUX-2 study from the general population in Luxembourg were analyzed. Objective sleep measures were assessed using accelerometers whereas subjective measures were assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Sleep measures were defined as predictors, while HbA1c and quantitative insulin sensitivity check index (QUICKI) scores were considered outcomes. Linear and spline regression models were fitted by progressively adjusting for demographic and lifestyle variables in the total sample population as well as by stratified analyses using gender, obesity status, depressive symptoms and diabetes status. RESULTS: In fully adjusted models, total and deep sleep durations were associated with lower HbA1c (mmol/mol) levels, whereas sleep coefficients of variation (%) and poor sleep efficiency, as measured by PSQI scores (units), were associated with higher HbA1c levels. In stratified models, such associations were observed mainly in men, and in subjects who had depressive symptoms, were overweight and no diabetes. In addition, total sleep, deep sleep, coefficients of variation and poor sleep efficiency as measured by PSQI revealed non-linear associations. Similarly, greater insulin sensitivity was associated with longer total sleep time and with PSQI-6 (use of sleep medication). CONCLUSION: Associations were more frequently observed between sleep characteristics and glycaemic control with the use of objective sleep measures. Also, such associations varied within subgroups of the population. Our results highlight the relevance of measuring sleep patterns as key factors in the prevention of diabetes.

Association of previous injury and speed with running style and stride-to-stride fluctuations.

Running-related injuries remain problematic among recreational runners. We evaluated the association between having sustained a recent running-related injury and speed, and the strike index (a measure of footstrike pattern, SI) and spatiotemporal parameters of running. Forty-four previously injured and 46 previously uninjured runners underwent treadmill running at 80%, 90%, 100%, 110%, and 120% of their preferred running speed. Participants wore a pressure insole device to measure SI, temporal parameters, and stride length (S(length)) and stride frequency (S(frequency)) over 2-min intervals. Coefficient of variation and detrended fluctuation analysis provided information on stride-to-stride variability and correlative patterns. Linear mixed models were used to compare differences between groups and changes with speed. Previously injured runners displayed significantly higher stride-to-stride correlations of SI than controls (P = 0.046). As speed increased, SI, contact time (T(contact)), stride time (T(stride)), and duty factor (DF) decreased (P < 0.001), whereas flight time (T(flight)), S(length), and S(frequency) increased (P < 0.001). Stride-to-stride variability decreased significantly for SI, T(contact), T(flight), and DF (P ≤ 0.005), as did correlative patterns for T(contact), T(stride), DF, S(length), and S(frequency) (P ≤ 0.044). Previous running-related injury was associated with less stride-to-stride randomness of footstrike pattern. Overall, runners became more pronounced rearfoot strikers as running speed increased.

Can parallel use of different running shoes decrease running-related injury risk?

The aim of this study was to determine if runners who use concomitantly different pairs of running shoes are at a lower risk of running-related injury (RRI). Recreational runners (n = 264) participated in this 22-week prospective follow-up and reported all information about their running session characteristics, other sport participation and injuries on a dedicated Internet platform. A RRI was defined as a physical pain or complaint located at the lower limbs or lower back region, sustained during or as a result of running practice and impeding planned running activity for at least 1 day. One-third of the participants (n = 87) experienced at least one RRI during the observation period. The adjusted Cox regression analysis revealed that the parallel use of more than one pair of running shoes was a protective factor [hazard ratio (HR) = 0.614; 95% confidence interval (CI) = 0.389-0.969], while previous injury was a risk factor (HR = 1.722; 95%CI = 1.114-2.661). Additionally, increased mean session distance (km; HR = 0.795; 95%CI = 0.725-0.872) and increased weekly volume of other sports (h/week; HR = 0.848; 95%CI = 0.732-0.982) were associated with lower RRI risk. Multiple shoe use and participation in other sports are strategies potentially leading to a variation of the load applied to the musculoskeletal system. They could be advised to recreational runners to prevent RRI.