Association Between Serum Cotinine Level and Serological Markers of Epstein-Barr Virus in Healthy Subjects in South China Where Nasopharyngeal Carcinoma Is Endemic.

Introduction: Self-reported smoking has been associated with higher seropositivity for the IgA response to Epstein-Barr virus (EBV) viral capsid antigen (VCA-IgA) and transcription activator protein (Zta) in healthy men in southern China where nasopharyngeal carcinoma (NPC) is endemic. Results on the association of biochemically verified smoking status with EBV reactivation are scarce. We aimed to investigate the relations of serum cotinine level with serological markers of EBV in healthy women, in addition to men. Methods: We collected information on demographic, lifestyle, environmental factors, and EBV serological markers in a cross-sectional study on 2,275 healthy subjects who were recruited from physical examination centers in Guangdong Province, China. In the present analysis, 901 subjects' serum cotinine levels have been measured by enzyme-linked immunosorbent assay (ELISA). Odds ratios (seropositivity of four EBV serological markers vs. seronegativity) for categorical serum cotinine levels were calculated by unconditional logistic regression with a group-specific confidence interval (CI). Results: In women, compared with lower serum cotinine level (0-0.71 ng/ml), higher cotinine level (>0.71-1.20 ng/ml; >1.20-228.40 ng/ml) was associated but non-significantly with higher seropositivity for EBV VCA-IgA (age- and education-adjusted OR = 1.18, 95% CIs = 0.84-1.64, 1.06, 0.75-1.50). These associations remained but still non-significant after adjusting for 5-year age group, education, family history of cancer, consumption of tea, Chinese herbal tea, salted fish at childhood, and exposure to occupational dust, chemical, fume, and radiation (multivariable adjusted OR = 1.21, 95% CIs = 0.85-1.71, 1.09, 0.76-1.55). In men, compared with lower serum cotinine level (0-2.15 ng/ml), higher cotinine level (>2.15-103.6 ng/ml; >103.6-419.4 ng/ml) was significantly associated with higher seropositivity for EBV VCA-IgA and Zta-IgA (age- and education-adjusted OR = 2.16, 95% CIs = 1.37-3.41, 1.79, 1.11-2.90; 1.98, 1.17-3.34, 1.95, 1.14-3.34). The association remained significant after adjusting for potential confounders for Zta-IgA (OR = 2.32, 95% CI = 1.37-3.93 for >2.15-103.6, and 2.50, 1.43-4.38 for >103.6-419.4 ng/ml), but not for VCA-IgA (2.06, 1.29-3.27, and 1.61, 0.96-2.71). Conclusions: Higher serum cotinine level is associated with higher seropositivity for EBV serological markers in healthy men in southern China. Such positive association was also observed in women but became non-significant. If confirmed to be causal, this finding has important implications for tobacco control and prevention of EBV-related disease, particularly for NPC.

Associations between environmental factors and serological Epstein-Barr virus antibodies in patients with nasopharyngeal carcinoma in South China.

Epstein-Barr virus (EBV) reactivation, reflected by aberrantly increased levels of various serological antibodies, has been suggested to be an early indicator of nasopharyngeal carcinoma (NPC) onset and progression. We have previously suggested that certain lifestyle and dietary factors were associated with elevated serological levels of the antibody against various EBV antigens namely VCA, Zta, EBNA1, and oral EBV DNA loads among healthy population. It remains unclear whether these potential environmental factors would also influence EBV serological antibodies in NPC patients. We conducted an epidemiological study to evaluate the associations between such environmental factors and EBV antibody levels among 1701 NPC patients in South China. Pretreatment serums were collected and examined for VCA-IgA and EA-IgA by immunoenzymatic assays and antienzyme rate (AER) of EBV DNase-specific neutralizing antibody. We found that consumption of Canton-style herbal tea was significantly correlated with increased serological antibody levels of VCA-IgA and EA-IgA, with adjusted ORs of 1.35 (95% CI: 1.03-1.76) and 1.32 (95% CI: 1.01-1.73), respectively, in the weekly intake frequency stratum, while not related to AER of EBV DNase-specific neutralizing antibody. Smoking was found to be not only an apparent risk factor for higher antibody levels of AER in stage III-IV patients (OR = 1.60, 95% CI: 1.11-2.30), but also associated closely with NPC stage at diagnosis (OR = 2.17, 95% CI: 1.47-3.22), with dose-response effects. In conclusion, we found consumption of Canton-style herbal tea and cigarette smoking were in positive associations with elevated EBV antibodies in NPC patients, which may be of public health significance for the primary prevention of EBV-associated diseases especially NPC.

Association of dietary fat intake with the risk of hip fractures in an elderly Chinese population: A matched case-control study.

AIM: The aim of the present study was to examine the association between dietary fat intake and the risk of hip fractures in an elderly Chinese population. METHODS: A case-control study of 646 patients with newly diagnosed hip fractures and 646 controls, matched by age (±3 years) and sex, was carried out among elderly Chinese (55-80 years) in Guangdong, China. Their dietary fat intake was measured and calculated using a 79-item food-frequency questionnaire. RESULTS: After adjusting for potential confounders, a dose-dependent increased risk of hip fractures was found to be associated with higher intakes of total fat, animal fat, saturated fatty acids and mono-unsaturated fatty acids (P for trend < 0.005). The adjusted odds ratios (95% confidence intervals) for hip fractures from a comparison of extreme quartiles were 1.92 (1.26-2.92) for total fat, 2.60 (1.70-3.99) for animal fat, 1.95 (1.30-2.93) for saturated fatty acids and 2.22 (1.46-3.39) for animal mono-unsaturated fatty acids, respectively. No significant association was observed for plant fat or polyunsaturated fatty acids (P for trend = 0.063 for plant fat and 0.174 for polyunsaturated fatty acids). CONCLUSIONS: Our findings suggest that higher consumption of total fat and animal fat rich in saturated fatty acids might increase the risk of hip fractures in elderly Chinese.

Associations between the dietary intake of antioxidant nutrients and the risk of hip fracture in elderly Chinese: a case-control study.

The role of oxidative stress in skeletal health is unclear. The present study investigated whether a high dietary intake of antioxidant nutrients (vitamins C and E, ß-carotene, animal-derived vitamin A, retinol equivalents, Zn and Se) is associated with a reduced risk of hip fracture in elderly Chinese. This 1:1 matched case-control study involved 726 elderly Chinese with hip fracture and 726 control subjects, recruited between June 2009 and May 2013. Face-to-face interviews were conducted to determine habitual dietary intakes of the above-mentioned seven nutrients based on a seventy-nine-item FFQ and information on various covariates, and an antioxidant score was calculated. After adjustment for potential covariates, dose-dependent inverse associations were observed between the dietary intake of vitamin C, vitamin E, ß-carotene, and Se and antioxidant score and the risk of hip fracture (P for trend ≤ 0·005). The OR of hip fracture for the highest (v. lowest) quartile of intake were 0·39 (95 % CI 0·28, 0·56) for vitamin C, 0·23 (95 % CI 0·16, 0·33) for vitamin E, 0·51 (95 % CI 0·36, 0·73) for ß-carotene, 0·43 (95 % CI 0·26, 0·70) for Se and 0·24 (95 % CI 0·17, 0·36) for the antioxidant score. A moderate-to-high dietary intake of retinol equivalents in quartiles 2-4 (v. 1) was found to be associated with a lower risk of hip fracture (OR range: 0·51-0·63, P< 0·05). No significant association was observed between dietary Zn or animal-derived vitamin A intake and hip fracture risk (P for trend >0·20). In conclusion, a higher dietary intake of vitamins C and E, ß-carotene, and Se and a moderate-to-high dietary intake of retinol equivalents are associated with a lower risk of hip fracture in elderly Chinese.

[A case-control study regarding tea consumption and risk of hip fractures in middle-aged and elderly Chinese].

OBJECTIVE: To assess the impact of tea consumption on the risk of osteoporotic hip fractures. METHODS: Between January 2008 and June 2012, 581 (148 males, 433 females) incident cases of hip fractures were enrolled from four hospitals in Guangdong province, with 581 sex- and age-matched (± 3 years) controls from either hospitals or communities. Face-to-face interviews were conducted to collect data pertaining to tea drinking and various covariates. RESULTS RESULTS: from univariate conditional logistic analyses showed that an inverse association was observed in tea drinking and hip fracture risk. Longer time, greater frequency and dosage of tea consumption were dose-dependently associated with lower risk of hip fractures (P-trend < 0.05). Compared to non-drinkers, the odd ratios related to regular tea drinkers, subgroups with different length, frequency, dosage, type of tea consumption were ranged between 0.54 and 0.74 (all P < 0.05). After adjustment for factors as age, daily energy intake, BMI, education levels, passive smoking, calcium supplement and physical activity, the dose-dependent associations among above said factors still remained significant. However, the strength of the association lowered slightly. The beneficial effect of tea was significant only in men but not in women. Similar effects were found in subjects with different education levels. CONCLUSION: Regular tea drinking habit might decrease the risk of osteoporotic hip fractures in the elderly males.

Dietary patterns and the risk of hip fractures in elderly Chinese: a matched case-control study.

CONTEXT: Many studies have investigated the effects of individual foods or nutrients on bone health, but limited research has focused on dietary patterns. PURPOSE: We examined the association of dietary patterns with the risk of hip fractures in elderly Chinese. DESIGN: This 1:1 age- (±3 years) and gender-matched case-control study were performed between June 2009 and June 2012. SETTING: The study was conducted in Guangdong Province, China. PARTICIPANTS: A total of 581 pairs of hip fracture incident cases and controls (71 ± 7 years) were studied. Face-to-face interviews were conducted to assess dietary intake using a 79-item food frequency questionnaire, whereas general information was collected using structured questionnaires. Dietary patterns were identified by a principal components factor analysis. Univariate and multivariate conditional logistic regression were used to analyze the association. MAIN RESULT: We identified 4 dietary patterns: healthy, prudent, traditional, and high-fat. Dose-dependent lower risks of hip fracture were observed in relation to higher scores in the healthy dietary pattern related to high fruit and vegetable intake and in the prudent pattern typified by a higher intake of nuts, mushrooms, algae, and seafood but lower in grains, whereas the same were associated with lower scores in the high-fat dietary pattern (all P trend < .05). The adjusted odds ratios (95% confidence intervals) for hip fractures, comparing the extreme tertiles of the 3 patterns, were 0.42 (0.24-0.73) for healthy, 0.51 (0.28-0.90) for prudent, and 2.25 (1.38-3.69) for high-fat. No significant association was found between the traditional dietary pattern (with a high intake of Chinese herbal tea, double stewed soup, processed meat and fish, and organ meat) and hip fracture risk. CONCLUSIONS: Our findings suggest that the consumption of a healthy or prudent dietary pattern can protect against hip fractures, whereas a high-fat pattern promotes the incidence of such fractures.