[Plasma lipid level and incidence of dyslipidemia in workers of Chongqing enterprises and institutions].

OBJECTIVE: To examine the plasma lipid level and distribution of dyslipidemia in workers of Chongqing enterprises and institutions. METHODS: By using cluster sampling method, 20 000 workers of Chongqing enterprises and institutions aged 18 to 60 were selected as target population from January to October, 2009. We conducted questionnaire survey, physical and laboratory examinations including total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Workers were divided into 18 - 29 years old group, 30 - 39 years old group, 40 - 49 years old group and 50 - 60 years old group. Characteristic and distribution of dyslipidemia were analyzed. RESULTS: Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were significantly different in various age group (all P < 0.01). TC, TG, HDL-C and LDL-C levels in the 30 years and over groups were all significantly higher than in the under 30 years old group(all P < 0.01). The TG levels in the 40 - 49 years old group and the 50 - 60 years old group were similar (P > 0.05). After adjusting for age, TC, TG, HDL-C and LDL-C levels in males were all significantly higher than in females (all P < 0.01). The incidence of dyslipidemia in this population was 35.01% and significantly higher in males than that of females (58.27% vs. 11.01%, P < 0.01). The incidence of dyslipidemia increased with aging (P < 0.01). CONCLUSIONS: The prevalence of dyslipidemia is high in Chongqing enterprises and institutions. The incidence of dyslipidemia is higher in males than in females and higher among the 30 years and over workers than that of under 30 years old workers.

[Influencing factors on behavior related to HIV testing among female commercial sex workers based on the Structural Equation Model].

OBJECTIVE: To investigate the influencing factors on behavior related to HIV testing among female commercial sex workers under Structural Equation Model (SEM). METHODS: In Chongqing, Sichuan, Guangxi, Xinjiang provinces, 1613 female commercial sex workers were participated in a questionnaire survey. Factors on behaviors related to HIV testing among female commercial sex workers were analyzed based on SEM. RESULTS: Influencing factors on behaviors related to HIV testing among female commercial sex workers would include social status, knowledge on AIDS, risk through self-evaluation, condom use, frequency of sexual services etc. GFI, AGFI, RMR were 0.9952, 0.9898 and 0.0115 respectively. CONCLUSION: Social status, knowledge on AIDS, risk through self-evaluation, condom use and frequency of sexual services were affecting the behaviors related to HIV testing among female commercial sex workers.

[Utility of waist-to-height ratio in detecting central obesity and related adverse cardiovascular risk among normal weight adults].

OBJECTIVE: To detect central obesity and related adverse cardiovascular disease risk factors by waist-to-height ratio (WHR) among normal weight adults in Chongqing area. METHODS: A total of 20 000 participants aged 18 - 59 from one hour economic cycle of Chongqing area were selected by group sampling method. We measured the height, waist circumference (WC), body weight, blood pressure, blood lipid and blood sugar. Body Mass Index (BMI) and WHR were computed. We analyzed the differences of the correlated indexes between non-central obesity group (WHR < 0.5) and central obesity group (WHR ≥ 0.5) of those had normal weight (18.5 ≤ BMI (kg/m(2)) < 24). And we used logistic regression method to analyze the relation between central obesity and related adverse cardiovascular risk factors. RESULTS: Among 11 612 normal weight subjects, 1801 (15.51%) participants were normal weight central obesity. Of non-central obesity group and central obesity group, the levels of waist WC were (73.71 ± 5.91) and (84.47 ± 4.58) cm (F = 328.74, P < 0.01); diastolic blood pressure levels were (72.85 ± 10.30) and (78.22 ± 11.90) mm Hg (1 mm Hg = 0.133 kPa, F = 23.62, P < 0.01); triglyceride levels were (1.22 ± 0.95), (1.97 ± 1.91) mmol/L (F = 114.70, P < 0.01); total cholesterol levels were (4.66 ± 0.84) and (5.04 ± 0.92) mmol/L (F = 13.10, P < 0.01); high density lipoprotein levels were (1.41 ± 0.31), (1.25 ± 0.29) mmol/L (F = 29.44, P < 0.01); low density lipoprotein levels were (2.65 ± 0.74) and (3.03 ± 0.77) mmol/L (F = 9.98, P < 0.01); glycemia levels were (4.94 ± 0.82) and (5.25 ± 1.37) mmol/L (F = 47.21, P < 0.01). The results of the logistic regression analysis showed the central obesity normal weight group was 1.28 (1.02 - 1.60), 1.49 (1.20 - 1.84), 2.24 (1.92 - 2.60), 1.77 (1.53 - 2.05), 1.58 (1.15 - 2.16) and 1.31 (1.06 - 1.63) times more likely than the normal group to have significantly elevated levels of systolic blood pressure, diastolic blood pressure, triglyceride, high density lipoprotein, low density lipoprotein and blood glucose. CONCLUSION: WHR can effectively reflect the normal weight central obesity and the risk factors of cardiovascular disease;the adverse cardiovascular disease risk was high among normal weight central obesity adults.

Kinetic substrate quantification by fitting the enzyme reaction curve to the integrated Michaelis-Menten equation.

The reliability of kinetic substrate quantification by nonlinear fitting of the enzyme reaction curve to the integrated Michaelis-Menten equation was investigated by both simulation and preliminary experimentation. For simulation, product absorptivity epsilon was 3.00 mmol(-1) L cm(-1) and K(m) was 0.10 mmol L(-1), and uniform absorbance error sigma was randomly inserted into the error-free reaction curve of product absorbance A(i) versus reaction time t(i) calculated according to the integrated Michaelis-Menten equation. The experimental reaction curve of arylesterase acting on phenyl acetate was monitored by phenol absorbance at 270 nm. Maximal product absorbance A(m) was predicted by nonlinear fitting of the reaction curve to Eq. (1) with K(m) as constant. There were unique A(m) for best fitting of both the simulated and experimental reaction curves. Neither the error in reaction origin nor the variation of enzyme activity changed the background-corrected value of A(m). But the range of data under analysis, the background absorbance, and absorbance error sigma had an effect. By simulation, A(m) from 0.150 to 3.600 was predicted with reliability and linear response to substrate concentration when there was 80% consumption of substrate at sigma of 0.001. Restriction of absorbance to 0.700 enabled A(m) up to 1.800 to be predicted at sigma of 0.001. Detection limit reached A(m) of 0.090 at sigma of 0.001. By experimentation, the reproducibility was 4.6% at substrate concentration twice the K(m), and A(m) linearly responded to phenyl acetate with consistent absorptivity for phenol, and upper limit about twice the maximum of experimental absorbance. These results supported the reliability of this new kinetic method for enzymatic analysis with enhanced upper limit and precision.