Nocturnal hypoxemic burden and micro- and macrovascular disease in patients with type 2 diabetes

Abstract

Background: Micro- and macrovascular diseases are common in patients with type 2 diabetes mellitus (T2D) and may be partly caused by nocturnal hypoxemia. The study aimed to characterize the composition of nocturnal hypoxemic burden and to assess its association with micro- and macrovascular disease in patients with T2D.

Methods: This cross-sectional analysis includes overnight oximetry from 1247 patients with T2D enrolled in the DIACORE (DIAbetes COhoRtE) study. Night-time spent below a peripheral oxygen saturation of 90% (T90) as well as T90 associated with non-specific drifts in oxygen saturation (T90_{non - specific}), T90 associated with acute oxygen desaturation (T90_desaturation) and desaturation depths were assessed. Binary logistic regression analyses adjusted for known risk factors (age, sex, smoking status, waist-hip ratio, duration of T2D, HbA1c, pulse pressure, low-density lipoprotein, use of statins, and use of renin-angiotensin-aldosterone system inhibitors) were used to assess the associations of such parameters of hypoxemic burden with chronic kidney disease (CKD) as a manifestation of microvascular disease and a composite of cardiovascular diseases (CVD) reflecting macrovascular disease.

Results: Patients with long T90 were significantly more often affected by CKD and CVD than patients with a lower hypoxemic burden (CKD 38% vs. 28%, p < 0.001; CVD 30% vs. 21%, p < 0.001). Continuous T90_desaturation and desaturation depth were associated with CKD (adjusted OR 1.01 per unit, 95% CI [1.00; 1.01], p = 0.008 and OR 1.30, 95% CI [1.06; 1.61], p = 0.013, respectively) independently of other known risk factors for CKD. For CVD there was a thresholdeffect, and only severly and very severly increased T90_non-specific was associated with CVD ([Q3;Q4] versus [Q1;Q2], adjusted OR 1.51, 95% CI [1.12; 2.05], p = 0.008) independently of other known risk factors for CVD.

Conclusion: While hypoxemic burden due to oxygen desaturations and the magnitude of desaturation depth were significantly associated with CKD, only severe hypoxemic burden due to non-specific drifts was associated with CVD. Specific types of hypoxemic burden may be related to micro- and macrovascular disease.

Keywords: Cardiovascular disease; Chronic kidney disease; Hypoxemic burden; Hypoxia; Type 2 diabetes.

Fig. 1

Study flow chart

Fig. 2

Prevalence of chronic kidney disease according to the presence of hypoxemic burden for T90, T90_{non−specific} and T90_desaturation, ODI, and desaturation depth. CKD chronic kidney disease, Desat Depth Desaturation depth, ODI oxygen desaturation index, T90 night-time spent with oxygen saturation < 90%, T90 desaturation T90 associated with acute oxygen desaturation events accompanied by resaturation, T90 non-specific T90 associated with non-specific and non-cyclic drifts in SpO2 or incomplete resaturation, Q quartile. * p<0.05, **** p<0.0001

Fig. 3

Prevalence of cardiovascular disease according to the presence of hypoxemic burden for T90, T90_{non−specific} and T90_desaturation, ODI, and desaturation depth. CVD cardiovascular disease, Desat Depth Desaturation depth, ODI oxygen desaturation index, T90 night-time spent with oxygen saturation <90%, T90 desaturation T90 associated with acute oxygen desaturation events accompanied by resaturation, T90 non-specific T90 associated with non-specific and non-cyclic drifts in SpO₂or incomplete resaturation, Q quartile. * p<0.05, **** p<0.0001