Relationship between obstructive sleep apnoea syndrome and essential hypertension: a dose-response meta-analysis.

OBJECTIVE: The objective of this study was to summarize the evidence regarding the relationship between obstructive sleep apnoea syndrome (OSAS) and the risk of essential hypertension. METHODS: The study was a dose-response meta-analysis of observational studies. The PubMed, Embase, CNKI, VIP and CBM databases were searched to collect relative studies examining the relationship between OSAS and the risk of essential hypertension. Studies were retrieved from database establishment through September 2016, and new literature published between September 2016 and May 2017 was later supplemented. Linear and non-linear dose-response models were used to assess the relationship between apnoea-hypopnea index (AHI), which was used to reflect the severity of OSAS, and the risk of essential hypertension. Stata 13.0 was used for the meta-analysis. RESULTS: Six prospective cohort studies and one case-control study were included, for a total sample size of 6098. The dose-response meta-analysis showed that a high AHI significantly increased the risk of essential hypertension compared with a low AHI (odds ratio (OR) = 1.77, 95% confidence interval (CI) (1.30, 2.41), p = 0.001). The linear dose-response meta-analysis showed that the risk of essential hypertension increased by 17% for every 10 events/h increase in the AHI (OR = 1.17, 95% CI (1.07, 1.27), p = 0.001), and the results of the non-linear dose-response meta-analysis showed that the risk of essential hypertension increased with increasing AHI value. CONCLUSION: A potential dose-response relationship exists between the severity of OSAS and the risk of essential hypertension. This relationship should be considered when developing prevention measures for essential hypertension.

[Spatial data based study of distribution of hepatitis C in Chongqing].

OBJECTIVE: To understand the spatial distribution of hepatitis C in Chongqing and its influencing factors. METHODS: The surveillance data of hepatitis C in 38 counties in Chongqing from January 2010 to December 2014 were collected, and spatial autocorrelation analysis and spatial regression analysis were conducted respectively by using software GeoDa 1.6.7. RESULTS: The reported incidence of hepatitis C in Chongqing ranged from 7.3/100,000 to 13.6/100,000 during 2010-2014, with the annual reported incidence of 10.3/100,000. The global Moran's I values were 0.478, 0.503, 0.529, 0.438, 0.406 respectively (P<0.05). The local spatial autocorrelation analysis indicated there were 6, 4, 7, 5 and 6 areas with high incidences of hepatitis C in 2010, 2011, 2012, 2013 and 2014 respectively. Spatial regression analysis revealed that the reported incidence of hepatitis C in Chongqing was associated with the urbanization rate (Z=2.126, P=0.033). CONCLUSIONS: The spatial distribution of hepatitis C in Chongqing from 2010 to 2014 was highly clustered. The hot spot of hepatitis C were mainly in the core areas and extended areas with well-developed economy, however the cold spot were in southeastern ecological reserve area with less developed economy. Urbanization had a certain positive influence on the distribution of hepatitis C in Chongqing.

[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.