Intraocular Pressure: the Effect of Short-term Fasting and Its Association With Fluid and Fat Status

@#Introduction: Short-term fasting may influence intraocular pressure (IOP) due to alteration of fluid (total body water; TBW, and water intake) and fat (total body fat; TBF). This study aimed: i) to compare IOP values within and between, fasting and non-fasting periods; and ii) to assess the association between IOP and, TBW and TBF. Methods: Thirty healthy participants aged 21.8±1.1 years were assessed on two different periods (fasting vs. non-fasting). During each period, the IOP, TBW and TBF values were assessed for four times (morning, afternoon, evening, late-evening). The IOP was measured using AccuPen® tonopen, while TBW and TBF were assessed by using a Tanita body composition analyser. Results: During fasting, the IOP value in the afternoon (14.53±2.33 mmHg) was significantly higher than in the evening (12.43±2.73 mmHg, p=0.009) and late-evening (12.60±2.44 mmHg, p=0.003). No significant difference in IOP was observed during non-fasting period. The mean of IOP in the evening was significantly lower during fasting compared to non-fasting (12.43±2.73 mmHg vs 13.75±2.53 mmHg, p=0.044). The IOP and TBW were negatively correlated (r=-0.268; p=0.011) during non-fasting and showed no association during fasting period. There was no significant correlation between IOP and TBF during both fasting and non-fasting periods. Conclusion: IOP reduction during short-term fasting, together with the no association with TBF and TBW suggested that IOP is an independent factor that reduces during fasting in healthy population.

The Efficacy of Body Mass Index and Total Body Fat Percent in Diagnosis Obesity according to Menopausal Status

OBJECTIVES: Body mass index (BMI) is commonly used in epidemiological study or clinical center. However, it is not exactly correlated with body fat composition and does not reflect sex, age, or race. The aim of this article is to evaluate the validity of BMI standards relative to total body fat (TBF) and to estimate new BMI criteria that correspond to TBF for obesity, especially for Asian postmenopausal women. METHODS: A total 3,936 patients were included in this cross-sectional study, including 1,565 premenopausal and 2,371 postmenopausal women. At the time of visit, demographic data were collected. We demonstrated the validity of BMI cut-point of 25 kg/m2 by using area under the curve (AUC), and presented the empirical optimal BMI cut-point by using Youden's index and overall accuracy in both premenopausal and postmenopausal women. RESULTS: BMI-defined obesity (≥ 25 kg/m2) represents high AUC values (> 0.9) for each TBF. In premenopausal women, TBF ≥ 38% and corresponding BMI value was 29.45 kg/m2 indicated the highest both Youden's index and overall accuracy. In comparison, postmenopausal women who were TBF ≥ 38% showed the highest Youden's index and overall accuracy, and corresponding BMI value was 26.45 kg/m2. CONCLUSIONS: We proposed new BMI criteria for obesity by using TBF reference. With application of bioelectrical impedance analysis, the diagnosis of obesity using BMI criteria may differ between premenopausal and postmenopausal women.

The relationship between body mass index, total body fat, body fat distribution, and dyslipidemia in the elderly / 中华临床营养杂志

Objective To investigate the relationship between body mass index (BMI),total body fat (TBF),body fat distribution,and dyslipidemia in the elderly.Methods A total of 395 healthy elderly people who had annual examination at Peking Union Medical College Hospital were consecutively enrolled from October 2013 to March 2014.Body weight (BW),TBF,abdominal fat (AF),visceral fat (VF),visceral fat area (VFA) and waist-to-hip ratio (WHR) were measured with multi-frequency bioelectric impedance analysis.Serum triglyceride (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured at the same time.The relationship between BMI,TBF,body fat distribution,and dyslipidemia were analyzed.Results The incidences of obesity (17.8％ vs.9.6％,P=0.036),overweight (49.6％ vs.30.4％,P=0.000) and dyslipidemia (67.0％ vs.44.8％,P =0.000) in male were significantly higher than those in female;while female showed a significantly higher percentage of TBF (60.0％ vs.41.1％,P =0.001).TC was positively correlated with TBF (P =0.020),AF (P =0.018),VF (P =0.015) and VFA (P =0.017);TG was positively correlated with BMI (P =0.000),TBF (P=0.000),WHR (P=0.000),AF (P=0.000),VF (P=0.000) and VFA (P=0.000);LDL-C was positively correlated with BMI (P =0.049),TBF (P =0.005),AF (P =0.004),VF (P =0.003) and VFA (P =0.004);while HDL-C was negatively correlated with BMI (P =0.000),TBF (P=0.020),WHR (P=0.000),AF (P=0.021),VF (P=0.024) and VFA (P=0.022).Receiver operating characteristic curve analysis showed that the predictive curves of BMI,TBF,WHR,AF,VF and VFA were above the reference line.TBF (P =0.000),WHR (P =0.000),AF (P =0.000),VF (P =0.000),VFA (P =0.000),TG (P =0.000) and LDL-C (female:P =0.021) in obesity/overweight group were significantly higher than those in normal weight group.Conclusion Obesity/overweight,high TBF and large WHR may increase the risk of dyslipidemia in the elderly.

Gender differences in body fat distribution of 3- to 6-year-old japanese children / 体力科学

A study was conducted to assess gender differences of body fat distribution (i. e., total body fat mass, subcutaneous fat mass, and internal fat mass) in a homogeneous group of Japanese children. Body composition was estimated in 141 boys and 139 girls (aged 3-6 yr) using bioelectrical impedance analysis (BIA) . All subjects were apparently healthy. Determinations of impedance were made using a four-terminal impedance analyzer (TP-95 K, Toyo Physical, Inc., Fukuoka) . The lean body mass (LBM) was calculated using the equation of Kushuner et al. (1992) and Goran et al. (1993) . Total body fat mass (TFM) was calculated as the difference between body weight and LBM. The subcutaneous fat mass (SFM) was calculated using a modification of the equation derived by Skerjl et al. (1953) . The internal fat mass (IFM) was calculated as the difference between TFM and SFM. From ages 3 through 6 years, the mean LBM increased with age in boys and girls, but showed no significant gender differences. There were also no obvious gender differences in TFM and IFM within the same age range. Percentage body fat decreased in both sexes until the age of approximately 5-yr, and then increased again slightly at 6 yr, although it showed no significant differences between the sexes. The gender-specific pattern of fat accumulation during childhood was characterized by an almost steady increase of SFM in girls. These differences were independent of gender differences in physical characteristics.