Accelerometer-measured sedentary time and cardiometabolic biomarkers: A systematic review

- Sedentary time was consistently, unfavourably associated with insulin sensitivity.
- Sedentary time was unfavourably associated with insulin, HOMA-IR and triglycerides.
- Breaks in sedentary time were favourably associated with triglycerides.
- Methods of measuring and analysing sedentary time need to be standardised.

ObjectiveWe conducted a systematic review to investigate the cross-sectional and prospective associations of accelerometer-measured total sedentary time and breaks in sedentary time with individual cardiometabolic biomarkers in adults ≥ 18 years of age.MethodsOvid Medline, Embase, Web of Science and the Cochrane Library were searched for studies meeting the inclusion criteria. Due to inconsistencies in the measurement and analysis of sedentary time, data was synthesised and presented narratively rather than as a meta-analysis.ResultsTwenty-nine studies were included in the review; twenty-eight reported on total sedentary time and six on breaks in sedentary time. There was consistent evidence from cross-sectional data of an unfavourable association between total sedentary time and insulin sensitivity. There was also some evidence that total sedentary time was unfavourably associated with fasting insulin, insulin resistance and triglycerides. Furthermore, there was some evidence from cross-sectional data of a favourable association between breaks in sedentary time and triglycerides.ConclusionTotal sedentary time was consistently shown to be associated with poorer insulin sensitivity, even after adjusting for time spent in physical activity. This finding supports the proposed association between sedentary time and the development of Type 2 diabetes and reinforces the need to identify interventions to reduce time spent sedentary.