Ambulatory arterial stiffness index is higher in hypertensive patients with chronic kidney disease

Ambulatory arterial stiffness index correlates with ambulatory pulse pressure but not dipping status in patients with grade 1/grade 2 essential hypertension

OBJECTIVE

To evaluate the relationship between ambulatory arterial stiffness index (AASI) and other parameters derived from ambulatory blood pressure (BP) monitoring, including dipping status, in patients with grade 1/grade 2 hypertension.

METHODS

This retrospective analysis included baseline data from Chinese outpatients enrolled into a previous study, who had clinic diastolic BP of 90-109 mmHg and systolic BP <180 mmHg, had undergone 24-h ambulatory BP monitoring and routine blood chemistry investigations, and had estimated glomerular filtration rate (eGFR) data.

RESULTS

Out of 120 patients screened, 87 were included. No significant difference in 24-h AASI was found between dippers and nondippers. The 24-h AASI significantly correlated with age, systolic BP and pulse pressure, and inversely correlated with 24-h diastolic BP variation and eGFR. In dippers and nondippers, AASI correlated with daytime pulse pressure, daytime diastolic BP variation and eGFR; in nondippers, AASI also correlated with 24-h systolic BP and 24-h pulse pressure. The 24-h AASI was significantly associated with 24-h pulse pressure and daytime pulse pressure.

CONCLUSION

In patients with grade 1/grade 2 essential hypertension, AASI shows a significant correlation with ambulatory pulse pressure.

Fabrication of 3D Photoresist Structure for Artificial Capillary Blood Vessel

We propose a new method for fabricating artificial capillaries using direct laser writing. IP-L and Ormocomp are tested as photoresist materials. Three different microstructures were fabricated from IP-L: a porous hollow pipe microstructure, a 3 × 3 array of twig microstructures, and an array of hollow twig microstructures. Porous hollow pipe microstructures of different diameters were fabricated from Ormocomp, a biocompatible photoresist. These designs resemble capillaries. IP-L and Ormocomp fabrication parameters, such as laser power, numerical aperture, fabrication time, and fabrication model, are compared. Fabrication time is related to the fabrication model chosen during the direct laser writing process. Combined model fabrication is recommended over solid model fabrication because it results in shorter fabrication time and a more robust microstructure that is more likely to maintain its shape on the substrate after development. Laser power is another important parameter controlling fabrication. IP-L fabrication withstands up to 20 mW of laser power, unlike Ormocomp microstructures, which require laser power of less than 18 mW. IP-L and Ormocomp photoresist stiffness is also evaluated. The fabrication of artificial capillaries is important in developing vascular simulators that enable researchers to understand, for example, blood pressure in the kidney glomerulus.