RESUMEN
BACKGROUND: Asterion has been recognized as the external skull landmark for localization of the transverse and sigmoid sinus junction (TSJ). This study aimed to localize the asterion using the intersection of the Frankfurt horizontal plane (FHP) line and a vertical line from the mastoid tip, and to determine its relationship with the transverse and sigmoid sinuses. MATERIALS AND METHODS: Distances from the asterion to the FHP and vertical line were measured on 200 dry skulls (100 males and 100 females). In addition, 48 cadavers (24 males and 24 females) underwent asterion drilling, and the relationship with the transverse and sigmoid sinuses was recorded. RESULTS: In most skulls, the asterion was superior to the FHP line, with average distances of 0.5 ± 0.3 cm on both sides. Distances to the vertical line were 3.7 ± 0.4 cm and 3.9 ± 0.4 cm for the left and right sides, respectively. These distances were statistically significant different between sides but not between sexes. The location of asterion was mainly over the TSJ (54%) and transverse sinus (42%). The accuracy of a predictive method was evaluated in additional 10 cadavers. The predicted positions were located with distances ranging from 0 to 1.3 cm in the horizontal plane (0.4 ± 0.4 cm) and 0 to 0.7 cm in the vertical plane (0.3 ± 0.2 cm) from the asterion. CONCLUSIONS: This study confirms the anatomical relationship between the asterion and TSJ including the transverse sinus. Alternative method for localizing the asterion was also introduced.
RESUMEN
This study investigated the impact of comprehensive sleep patterns on glycaemic parameters and endothelial function in adolescents and young adults with type 1 diabetes (T1D). Thirty subjects with type 1 diabetes (aged 13-25) without chronic complications participated. For 1 week, glucose levels were monitored by real-time continuous glucose monitoring (CGM) and sleep was simultaneously assessed by actigraphy. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Flow-mediated dilatation (FMD) measured endothelial function at the brachial artery. Insulin sensitivity was determined by calculated estimated glucose disposal rate (eGDR). Glycaemic control was assessed using haemoglobin A1C (HbA1C) levels. To address potential confounding by metabolic syndrome on the FMD results, three affected subjects were excluded from FMD correlation analyses. Participants with PSQI scores >5 had a lower %FMD compared with those with scores ≤5 (4.6 ± 3.7% vs. 7.6 ± 3.0%, p = 0.03). Multivariate analysis indicated that lower sleep efficiency and higher sleep duration variability were associated with higher HbA1C levels (ß = -0.076, 95%CI [-0.145, -0.008], p = 0.029; ß = 0.012, 95%CI [0.001, 0.023], p = 0.033). Irregular sleep timing and lower sleep efficiency were related to decreased insulin sensitivity (sleep midpoint irregularity ß = -1.581, 95%CI [-2.661, -0.502], p = 0.004, and sleep efficiency ß = 0.147, 95%CI [0.060, 0.235], p = 0.001). No significant associations were found between glycaemic parameters and FMD. Our study demonstrated that sleep irregularity in type 1 diabetes was associated with glycaemic control and insulin resistance, while poor subjective sleep quality was linked to endothelial dysfunction. Promoting healthy sleep habits, including consistent sleep timing could benefit metabolic and cardiovascular health in type 1 diabetes.