METHODS: A total of 62 participants aged between 13 and 17y were involved. A self-administered questionnaires containing 12 items was used to evaluate the smartphone usage patterns. This was followed by an eye examination, involving a battery of accommodation and convergence assessments before and after the smartphone use. The data analysis comprised descriptive statistics, paired t-test, and correlation coefficients.
RESULTS: The use of smartphones is at a high level and at an optimal distance daily, with more than 6h a day watching video films, games, and completing school projects. Majority of the participants not reported eye strain factors and eye prescription changes with the use of digital devices. The use of a smartphone continuously for 30min was found to significantly decrease amplitude of accommodation, accommodative facility, and positive relative accommodation (P<0.001). Meanwhile, the lag of accommodation parameters and negative relative accommodation increased with the use of smartphones significantly (P<0.001). The near point of convergence (NPC) and distance and near negative fusional vergence decreased significantly (P<0.001). The NPC parameter was found to have a weak negative association with the frequency of smartphone use (R=-0.276, P<0.05).
CONCLUSION: Frequent and continuous use of smartphones have increased visual stress and resulted in weakness of accommodation and vergence functions. Therefore, frequent break is mandatory when using a smartphone and appropriate visual hygiene, the 20-20-20 rule (every 20min, view something 20 feet away for 20s) are required during smartphone use to maintain visual function.
PATIENTS AND METHODS: Fasting plasma PP concentrations were measured in 104 overweight and obese subjects (46 men and 58 women). In the same subjects, total and regional adipose tissue, including total visceral adipose tissue (VAT) and total subcutaneous adipose tissue (TSAT), were measured using whole-body magnetic resonance imaging. Intrahepatocellular lipid content (IHCL) was quantified by proton magnetic resonance spectroscopy.
RESULTS: Fasting plasma PP concentrations positively and significantly correlated with both VAT (r = 0.57, P < .001) and IHCL (r = 0.51, P < .001), but not with TSAT (r = 0.02, P = .88). Fasting PP concentrations independently predicted VAT after controlling for age and sex. Fasting PP concentrations independently predicted IHCL after controlling for age, sex, body mass index (BMI), waist-to-hip ratio, homeostatic model assessment 2-insulin resistance, (HOMA2-IR) and serum concentrations of triglyceride (TG), total cholesterol (TC), and alanine aminotransferase (ALT). Fasting PP concentrations were associated with serum ALT, TG, TC, low- and high-density lipoprotein cholesterol, and blood pressure (P < .05). These associations were mediated by IHCL and/or VAT. Fasting PP and HOMA2-IR were independently significantly associated with hepatic steatosis (P < .01).
CONCLUSIONS: Pancreatic polypeptide is a novel predictor of visceral and liver fat content, and thus a potential biomarker for cardiovascular risk stratification and targeted treatment of patients with ectopic fat deposition.