Novel oxygen desaturation parameters are associated with cardiac troponin I: Data from the Akershus Sleep Apnea Project

Abstract

Novel diagnostic markers for obstructive sleep apnea beyond the apnea-hypopnea index (AHI) have been introduced. There are no studies on their association with markers of subclinical myocardial injury. We assessed the association between novel desaturation parameters and elevated cardiac troponin I and T. Participants with polysomnography (498) from the Akershus Sleep Apnea study were divided into normal and elevated biomarker groups based on sex-specific concentration thresholds (cardiac troponin I: ≥4 ng/L for women, ≥6 ng/L for men; and cardiac troponin T: ≥7 ng/L for women, ≥8 ng/L for men). Severity of obstructive sleep apnea was evaluated with the AHI, oxygen desaturation index, total sleep time with oxygen saturation below 90% (T90), lowest oxygen saturation (Min SpO 2 %), and novel oxygen desaturation parameters: desaturation duration and desaturation severity. How the AHI and novel desaturation parameters predicted elevated cardiac troponin I and cardiac troponin T levels was assessed by the area

Comparative associations of oximetry patterns in Obstructive Sleep Apnea with incident cardiovascular disease

“…Other studies finding associations between metrics incorporating oxygen desaturation curve area and CVD outcomes or mortality have used a full spectrum of data from no disease to severe OSA [ 13 , 14 ]. In terms of the potential advantage of more novel oxygen desaturation assessments compared to AHI another recent study has looked at this using the outcome of subclinical myocardial injury (cardiac troponin levels) [ 40 ]. This study found AHI, ODI, and novel metrics (incorporating oxygen desaturation area) were all similarly useful, with no advantage of the novel metrics, in discriminating those with elevated troponin [ 40 ].…”

“…In terms of the potential advantage of more novel oxygen desaturation assessments compared to AHI another recent study has looked at this using the outcome of subclinical myocardial injury (cardiac troponin levels) [ 40 ]. This study found AHI, ODI, and novel metrics (incorporating oxygen desaturation area) were all similarly useful, with no advantage of the novel metrics, in discriminating those with elevated troponin [ 40 ]. A large OSA clinical cohort has found similar associations among ODI, T90, and “hypoxic burden” metrics in predicting major adverse CV events or all-cause mortality [ 34 ].…”

Time Spent with Saturation below 80% versus 90% in Patients with Obstructive Sleep Apnoea

“…There are several markers to measure hypoxaemic burden during sleep, including minimal saturation (MinSatO 2 ), the oxygen desaturation index (ODI), TST90%, sleep-apnoea-specific hypoxic burden (measured as the area under the desaturation curve associated with respiratory events) [ 23 , 24 ], desaturation duration (the cumulative time of desaturations) and desaturation severity (the sum of the areas of all desaturation events) [ 25 , 26 ]. Whilst the former three are readily available on sleep reports, the latter three need to be calculated with external software.…”

Time spent with saturation below 80% versus 90% in patients with obstructive sleep apnoea

“…There are several markers to measure hypoxaemic burden during sleep, including minimal saturation (MinSatO 2 ), the oxygen desaturation index (ODI), TST90%, sleep apnoea-speci c hypoxic burden (measured by the area under the desaturation curve associated with respiratory events) [22,23], desaturation duration (the cumulative time of desaturations) and desaturation severity (the sum of the areas of all desaturation events) [24,25]. Whilst the former three are readily available on sleep reports, the latter three need to be calculated with an external software.…”

“…Whilst the former three are readily available on sleep reports, the latter three need to be calculated with an external software. The merit of the latter indices is that they take into account both the depth and duration of desaturation; however, their additive value compared to TST90% is limited [22,24]; but might outperform TST90% in selected populations [22]. Time spent with saturation below 80% (TST80%) is a metric which is also often readily provided by the sleep studies and does not require further transformation.…”