Metabolically healthy obese subjects are at risk of fatty liver but not of pre-clinical atherosclerosis.

BACKGROUNDS AND AIMS: Whether obesity increases risk of cardiovascular disease (CVD) and fatty liver because of the co-existence of other risk factors is uncertain. We investigated odds ratios (ORs) for: a) a measure of pre-clinical atherosclerosis and b) fatty liver, in metabolically healthy obese (MHO) subjects, metabolically abnormal obese (MAO) subjects and metabolically abnormal non obese subjects (MANO), using a metabolically healthy non obese (MHNO) group as the reference. METHODS AND RESULTS: 14,384 South Koreans from an occupational cohort underwent cardiac computed tomography (CT) estimation of CAC score, liver ultrasound determination of fatty liver, and measurement of cardiovascular risk factors. Pre-clinical atherosclerosis was defined by a CAC score >0. We used logistic regression to determine ORs for CAC >0, and fatty liver in MHO, MAO and MANO subjects (reference group MHNO). There was no increase in OR for CAC score >0 (OR = 0.93, [95% CIs 0.67,1.31], p = 0.68), in the MHO group, whereas there was an increase in the ORs for CAC score >0 in the MAO, and MANO groups (OR = 1.64 [95% CI 1.36,1.98], p < 0.001) and (OR = 1.38 [95% CI 1.17,1.64], p < 0.001), respectively. In contrast, for fatty liver, there was an increase in OR in each group (OR = 3.63 [95% CI 3.06, 4.31] p < 0.001); (OR = 5.89 [5.18,6.70] p < 0.001); and (OR = 1.83 [95% CI 1.69,2.08]) in the MHO, MAO group and MANO groups respectively. CONCLUSION: MHO subjects are at risk of fatty liver but attenuated risk of pre-clinical atherosclerosis. Both MAO and MANO subjects are at risk of fatty liver and pre-clinical atherosclerosis.

Thermal stability of superhydrophobic, nanostructured surfaces.

The thermal stability of superhydrophobic, nanostructured surfaces after thermal annealing was explored. Flat surfaces coated with hydrophobic diamond-like carbon (DLC) via plasma polymerization of hexamethyldisiloxane (HMDSO) showed a gradual decrease in the water contact angle from 90(o) to 60(o) while nanostructured surfaces maintained superhydrophobicity with more than 150° for annealing temperatures between 25 and 300°C. It was also found that surfaces with nanostructures having an aspect ratio of more than 5.2 may maintain superhydrophobicity for annealing temperatures as high as 350°C; above this temperature, however, the hydrophobicity on surfaces with lower aspect ratio nanostructures gradually degraded. It was observed that regardless of the aspect ratios of the nanostructure, all superhydrophobic surfaces became superhydrophilic after annealing at temperatures higher than 500°C.