Progress on development and application of the diet-related inflammatory index in cancer epidemiological studies / 中华流行病学杂志

Cancer is a major public health problem worldwide, causing an more serious burden of disease. Inflammation is considered a predisposing factor for cancer with close relationship with its incidence. In recent years, the public and epidemiologists has paid more attention to the association between nutrition and cancer and other chronic diseases in the perspective of inflammation. This paper summarizes the development and application of the diet-related inflammatory index in cancer epidemiological studies based on the literature retrieval of common diet-related inflammatory index. Firstly, we highlight the common diet-related inflammatory indices and their construction methods, such as the Dietary Inflammatory Index, a literature-derived diet-related inflammatory index, and the Empirical Dietary Inflammatory Index, an empirically derived diet-related inflammatory index, and so on. Secondly, the epidemiological research progress on the commonly used diet-related inflammatory indices is briefly introduced. Finally, the advantages and disadvantages of the two types of this inflammatory indices are also briefly described for the purpose of providing reference for nutrition epidemiological studies of cancer and other chronic diseases in China.

Statistical methods for relative risk estimation and applications in case-cohort study / 中华流行病学杂志

Objective: To systematically introduce the design of case-cohort study and the statistical methods of relative risk estimation and their application in the design. Methods: First, we introduced the basic principles of case-cohort study design. Secondly, Prentice's method, Self-Prentice method and Barlow method were described in the weighted Cox proportional hazard regression models in detail, finally, the data from the Shanghai Women's Health Study were used as an example to analyze the association between obesity and liver cancer incidence in the full cohort and case-cohort sample, and the results of parameters from each method were compared. Results: Significant association was observed between obesity and risk for liver cancer incidence in women in both the full cohort and the case-cohort sample. In the Cox proportional hazard regression model, the partial regression coefficients of the full cohort and the case-cohort sample fluctuated with the adjustment of confounding factors, but the hazard ratio estimates of them were close. There was a difference in the standard error of the partial regression coefficient between the full cohort and the case-cohort sample. The standard error of the partial regression coefficient of the case-cohort sample was larger than that of the full cohort, resulting in a wider 95% confidence interval of the relative risk. In the weighted Cox proportional hazard regression model, the standard error of the partial regression coefficient of Prentice's method was closer to the parameter estimates from full cohort than Self-Prentice method and Barlow method, and the 95% confidence interval of hazard ratio was closer to that of the full cohort. Conclusions: Case-cohort design could yield parameter results closer to the full cohort by collecting and analyzing data from sub-cohort members and patients with the disease, and reduce sample size and improve research efficiency. The results suggested that Prentice's method would be preferred in case-cohort design.

Lifestyle-related factors and cancer incidence in men: a public health assessment based on a 'healthy lifestyle score' / 中华流行病学杂志

Objective To evaluate the effects of combined lifestyle-related factors and risk of cancer incidence among adult men in urban Shanghai.Methods Information was obtained from 60 817 men in the Shanghai Men' s Health Study (2002-2006) program and 2033 incident cancers who were confirmed at the end of 2009.A healthy lifestyle score (HLS) system was developed,based on five lifestyle-related factors,and participants were scored one point for each of the healthy behaviour:never smoked,alcohol intake less than 1 drink/day,under normal weight range (18.5-27.9 kg/m2),physical activity (≥ 54 Met-hours/week),fruit and vegetable intake ≥451 g/day,the else would score as zero.The total score would range from zero to five.Cox regression model was used to evaluate the associations between combined lifestyle-related factors and the cancer incidence.Results Compared to men having scores as zero or one,the hazard ratios (95％ confidence intervals) for men with two,three,four,five health behaviour scores were 0.77 (95％CI:0.66,0.90),0.67 (95％CI:0.58,0.78),0.56(95％ CI:0.47,0.65),0.51 (95％ CI:0.42,0.62),respectively.The population attributable risks for cancer incidence was 10.4％ for those having scores less than 3 items.Conclusion Never smoked,moderate alcohol intake,maintaining normal weight,being physically fit,and having enough daily fruit and vegetable intake were associated with lower risk of total cancer incidence in men.Our data showed that healthy lifestyle could significantly benefit the public health programs of the population.

Epidemiological characteristics of obesity and its relation to chronic diseases among middle aged and elderly men / 中华流行病学杂志

Objective To investigate the epidemiological characteristics of obesity and how they related to chronic diseases among middle aged and elderly men in urban Shanghai.Methods A cross-sectional analysis was conducted using data from a baseline survey from an on-going cohort study of 61 500 men between 40-74 of age in urban Shanghai.Study subjects were recruited from 8 communities of an urban district in Shanghai during 2002 to 2006.General obesity was measured by body mass index (BMI≥28) and,central obesity by waist to hip ratio (WHR≥0.9).Unconditional logistic regression model was used to estimate the odds ratio and 95% confidence interval of chronic diseases associated with obesity after adjustment for potential confounding factors.Results The aged-adjusted prevalence rates of overweight,overall obesity and central obesity were 36.8%,7.7% and 49.7% respectively.In this population,66.7% subjects had ever been diagnosed with one or more kinds of chronic diseases,in which hypertension ranked first with an age-adjusted prevalence rate of 26.5%.After mutual adjustment for WHR and BMI,obesity (BMI≥28) appeared to be associated with increased prevalence rates of hypertension,coronary heart disease,gallstone,urinary tract calculus and stroke comparing to men having normal BMI (18.5≤BMI＜24) with ORs ranged from 1.16 to 3.13.However,to the lowest quartile,the ORs associated with the highest WHR were between 1.20 and 1.69 for these 5 diseases.All P values for trend tests were less than 0.05.WHR was positively associated with diabetes,with OR as 2.40 (95% CI:2.14-2.70) for the highest quartile comparing to the lowest quartile.BMI was unrelated to the diabetes prevalence.Prevalence of chronic obstructive pulmonary disease decreased with increasing BMI,but increased with WHR.The corresponding OR was 0.87 (95% CI:0.77-0.98)for the obese men compared to those with normal BMI while 1.26(95%CI:1.14-1.40) for the subjects with the highest WHR comparing to those with the lowest WHR.Conclusion The prevalence rates of hypertension,gallstone,urinary tract calculus,cardiovascular and cerebrovascular diseases were higher in obesity men.Central obesity seemed to be related to high prevalence of diabetes.

Incidence trends of colorectal cancer in urban Shanghai, 1973 - 2005 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the time trends of colorectal cancer incidence rates in urban Shanghai from 1973 to 2005.</p><p><b>METHODS</b>Data on the incidence rates of colorectal cancer were obtained from a population-based cancer registry in Shanghai. A total of 32 962 colon cancer patients and 24 662 rectal cancer patients were registered. Population estimation were based on periodic censuses, with age- and sex-specific annual estimates derived for the remaining years. The rates were adjusted to the world standard population by using the direct method. Annul percent changes (APCs) in rates were estimated by means of a linear regression of the logarithm of the respective rates on calendar, weighted by the number of incidence cases.</p><p><b>RESULTS</b>The incidence rates of colorectal cancer increased steadily during 1973 to 2005, the age-adjusted incidence rates of colon cancer increased from 6.09 and 5.70 to 14.70 and 14.35 per 100 000 in male and female respectively. The APCs were 3.03% (t = 14.77, P < 0.01) and 3.21% (t = 22.15, P < 0.01). The rates of rectal cancer increased from 7.68 and 6.51 to 11.45 and 8.28 per 100 000 in male and female respectively. The APCs were 1.34% (t = 7.28, P < 0.01) and 0.93% (t = 7.34, P < 0.01). The top APCs for colon and rectal cancer in female were 5.86% and 2.79% at age above 85 and in male those were 4.64% and 2.38% at age of 80-. The APCs of colon cancer were greater than those of rectal cancer at the groups above 45 years old. The average ages when diagnosed were delayed from 57 - 60 to 66 - 70 during these 33 years. The average diagnosed ages of colon cancer were later than those of rectal cancer slightly (from 2003 to 2005, the onset age of male colon cancer: 68.61 +/- 12.17, male rectal cancer: 66.81 +/- 12.62, t = 4.90, P < 0.01; female colon cancer: 69.20 +/- 12.13, female rectal cancer: 67.75 +/- 12.54, t = 3.81, P < 0.01).</p><p><b>CONCLUSION</b>The incidence rates of colorectal cancer increased steadily during 1973 to 2005, especially for colon cancer. Further research is needed to identify the causes resulting in these changes.</p>

Anthropometry and female breast cancer: a prospective cohort study in urban Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the association between anthropometry and risk of breast cancer among pre-and post-menopausal women in urban Shanghai.</p><p><b>METHODS</b>A total of 73 461 female residents aged 40 to 70 years in urban Shanghai were recruited in a prospective cohort study (the Shanghai women's health study) during 1997 through 2000, and were actively followed up biennially. During mean follow-up period of 5.66 years, 432 incident cases of breast cancer were identified in the cohort. Cox regression model was used to estimate the adjusted relative risks (RRs) and 95% confidence intervals (CIs).</p><p><b>RESULTS</b>After adjustment for some potential confounding factors, baseline weight, body mass index(BMI), waist-to-hip ratio(WHR) and weight gain since age 20 were positively associated with the increased risk of breast cancer among postmenopausal women. The positive association between height and breast cancer was found among premenopausal women. Among them, those with height taller than 161 cm at age 20 experienced 1.84 fold increased risk (95% CI: 1.30-2.61) of breast cancer compared to their counterpart with height shorter than 157.1 cm. Women who were either much heavier or lighter than average at age 20 were at reduced risk. Further analyses mutually adjusted for BMI and WHR did not substantially alter the positive association for both BMI and WHR. After further adjustment for BMI, weight gain since age 20 was significantly associated to an increased risk for postmenopausal breast cancer (RR = 1.61, 95% CI: 1.09-2.37).</p><p><b>CONCLUSIONS</b>Weight gain and central obesity seemed to be strong predictors for the risk of breast cancer among postmenopausal women. Controlling weight and decreasing fat around waist were effective means to prevent postmenopausal breast cancer and height might serve as a risk factor for premenopausal breast cancer.</p>