Overweight, obesity, and cancer risk

The relationship of excess body weight and health-related quality of life: evidence from a population study in Taiwan

OBJECTIVE

Excess body weight is related to significant morbidity and mortality. However, less is known about the relationship of body weight to health-related quality of life (HRQOL), especially for Asian populations. We examined the relationship of excess weight and HRQOL in a general population sample from Taiwan.

RESEARCH METHODS AND PROCEDURES

This cross-sectional study used a national representative sample (n = 14,221) from the 2001 Taiwan National Health Interview Survey. Body weight was categorized using body mass index (BMI in kg/m2) as normal (18.5-24.9), overweight (25-29.9), and obese (> or = 30). HRQOL was measured using the Taiwan version of the SF-36. We compared the body weight-HRQOL relationships by age, gender, and status of chronic condition, respectively. We especially used the Generalized Estimating Equations (GEE) to examine the relationships of BMI and HRQOL by taking into account the correlations of HRQOL within households. Four models were developed to adjust sequentially for sets of covariates: Model 1 with no adjustment; Model 2 adjusting for sociodemographic variables; Model 3 adding chronic conditions; Model 4 further adding smoking status.

RESULTS

Unadjusted physical HRQOL was best for normal weight, worse for overweight, and worst for obese individuals. For unadjusted mental HRQOL, overweight subjects had at least as good mental domain scores of HRQOL as those with normal weight or obesity, depending on the subscales. As age increased, excess weight was associated with worse physical, but not mental HRQOL. Compared to men, women with excess weight showed a greater deficit in physical HRQOL. Multivariable analyses suggested that obesity was associated with worse physical HRQOL compared to overweight, which, in turn, was worse or comparable to normal weight. Specifically, in the model adjusting for demographic variables, the deficit in physical functioning and physical component scores for the obese vs normal weight were statistical significant (P < 0.05) and clinically important difference (effect size > or = 0.3). Both obesity and overweight were associated with higher mental component scores than normal weight, but the effect size was < 0.3.

CONCLUSION

In Taiwan, excess weight was related to worse physical, but not mental HRQOL. The lack of impact of increased body weight on mental health status presents a potential challenge to preventing the increases in obesity. More research is needed to elucidate the mechanisms by which excess weight affects specific domains of HRQOL, and to develop effective prevention strategies.

Anthropometrics, physical activity, related medical conditions, and the risk of non-hodgkin lymphoma

BACKGROUND

Recent reports suggest that obesity, or conditions associated with obesity, might be risk factors for non-Hodgkin lymphoma (NHL), a cancer with dramatically increasing incidence in western countries over the last several decades. Physical inactivity increases the risk of obesity and of type 2 diabetes, but there are few data on the association of physical activity with risk of NHL.

METHODS

We evaluated these factors in a population-based case-control study conducted in Detroit, Iowa, Los Angeles, and Seattle from 1998 to 2000. Incident HIV-negative NHL cases aged 20-74 years were rapidly reported in each area (n = 1321). Controls were identified through random digit dialing and Medicare files, and were frequency matched to cases on sex, age, race, and study site (n = 1057). Risk factor data were collected by in-person interviews and self-administered questionnaires. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI), adjusted for age, sex, race and study center.

RESULTS

High body mass index (OR = 1.73 for 35+ versus <25 kg/m2; 95% CI 1.15-2.59) and history of gallstones (OR = 1.95, 95% CI 1.11-3.40) were positively associated with diffuse NHL, but were not associated with follicular or all NHL combined. Height was positively associated with risk of all NHL combined (OR = 1.38 for >70 versus <65 inches; 95% CI 0.98-1.94), and positive associations were apparent for both diffuse and follicular NHL. Non-occupational physical activity was inversely associated with risk of all NHL combined (ORs with increasing level: 1, 0.75, 0.71, 0.55, 0.68; p-trend = 0.04) and for diffuse and follicular NHL. We observed no association of total energy intake, type 2 diabetes, or hypertension with risk of NHL. In a multivariable model to predict risk of diffuse NHL, BMI (OR = 2.15 for 35+ versus <25 kg/m2; 95% CI 1.09-4.25) and height (OR = 1.63 for 71+ versus <65 inches; 95% CI 0.75-3.57) were positively associated with risk while physical activity was weakly and inversely associated risk (ORs with increasing level: 1, 0.76, 0.72, 0.78, 0.82; p-trend = 0.9).

CONCLUSION

BMI and history of gallstones were positively associated with risk of diffuse NHL, supporting a role for obesity in this NHL subtype. Height was positively associated with NHL risk across subtypes, and suggests a role for early life nutrition in NHL risk. Non-occupational physical activity was only weakly and inversely associated with NHL risk after adjustment for obesity, height and alcohol use.

[Do we really follow the Mediterranean diet?]

OBJECTIVE

To discover people's nutritional habits and their distance from the Mediterranean diet.

DESIGN

Cross-sectional, descriptive study.

SETTING

Gavà 2 Health District, Barcelona, Spain.

PARTICIPANTS

614 obtained at random from patients attending the centre. Stratified in 3 age groups (15-35, 36-64, and over 64).

MAIN MEASUREMENTS

Validated questionnaire of the consumption by groups of food over the previous week. Then figures were compared with the standard values of the Mediterranean diet.

RESULTS

Outstanding results were: 60% insufficiency in consumption of carbohydrates; 70.7% insufficiency in green vegetables, fruit and root vegetables; 75% of optimum consumption of pulses; 64% deficient consumption of milk products; 66% optimum consumption of fish; 73.8% optimum consumption of eggs; 71.2% proper intake of white meat; 64.2% excessive consumption of red meat and processed meats, which reached 86.6% among 15-35 year olds. There was a BMI over 25 in 59% of women and 63% of men, with obesity being most common among women and people over 64 years old.

CONCLUSIONS

The population studied consumed an excessive amount of food with high contents of saturated fat, especially young people. There is a deficit in the intake of slowly absorbed carbohydrates and a less than ideal consumption of fruit, green vegetables and root vegetables, which was more marked among the young. The consumption of milk products was below the recommended amount. Pulses, fish and white meat were close to the right levels. This pattern is far from ideal and leads to higher risk of prevalent chronic illnesses.

Cause-specific mortality of grand multiparous women in Finland

Knowledge is limited on mortality of grand multiparous women (> or =5 deliveries), whose hormonal, metabolic, and social conditions differ from the average. The authors studied overall and cause-specific mortality in 1974-2001 among 87,922 grand multiparous women including 3,678 grand grand multiparous women (> or =10 deliveries) in Finland. Standardized mortality ratios were defined as ratios of observed to expected numbers of deaths, both derived from national cause-of-death files. During follow-up, 18,870 grand multiparous women and 625 grand grand multiparous women died (standardized mortality ratios (SMRs) = 0.95 and 1.01, respectively). Decreased mortality among grand multiparous women was found for cancers of the breast (SMR = 0.64, 95% confidence interval (CI): 0.59, 0.69), corpus uteri (SMR = 0.68, 95% CI: 0.56, 0.80), ovary (SMR = 0.68, 95% CI: 0.60, 0.75), bladder (SMR = 0.59, 95% CI: 0.41, 0.82), and respiratory tract (SMR = 0.80, 95% CI: 0.72, 0.88). The only malignant tumor associated with elevated mortality was kidney cancer (SMR = 1.38, 95% CI: 1.21, 1.56). The standardized mortality ratio was also low for dementia (SMR = 0.78, 95% CI: 0.72, 0.84), respiratory diseases (SMR = 0.80, 95% CI: 0.75, 0.85), and accidents and violent causes (SMR = 0.79, 95% CI: 0.73, 0.84). Mortality from diabetes mellitus (SMR = 1.42, 95% CI: 1.29, 1.55) and ischemic heart disease (SMR = 1.10, 95% CI: 1.08, 1.13) was increased. According to this study, overall mortality among grand multiparous women is not elevated. Low mortality from cancers is offset by higher mortality from cardiovascular conditions and diabetes mellitus.

Exploration of global gene expression in human liver steatosis by high-density oligonucleotide microarray

Understanding the molecular mechanisms underlying fatty liver disease (FLD) in humans is of major importance. We used high-density oligonucleotide microarrays (22.3 K) to assess the mechanisms responsible for the development of human liver steatosis. We compared global gene expression in normal (n=9) and steatotic (n=9) livers without histological signs of inflammation or fibrosis. A total of 34 additional human samples including normal (n=11), steatosis (n=11), HCV-related steatosis (n=4) or steatohepatitis associated with alcohol consumption (n=4) or obesity (n=4) were used for immunohistochemistry or quantitative real-time PCR studies. With unsupervised classification (no gene selection), all steatotic liver samples clustered together. Using step-down maxT multiple testing procedure for controlling the Family-Wise Error-Rate at level 5%, 110 cDNAs (100 over- and 10 underexpressed) were found to be differentially expressed in steatotic and normal livers. Of them were genes involved in mitochondrial phosphorylative and oxidative metabolism. The mean ratio of mitochondrial DNA to nuclear DNA content was higher in liver steatosis compared to normal liver biopsies (1.12+/-0.14 vs 0.67+/-0.10; P=0.01). An increased expression of genes involved in inflammation (IL-1R family, TGFB) was also observed and confirmed by quantitative RT-PCR or immunochemistry. In steatohepatitis, an increase of the protein expression of mitochondrial antigens, IL-1R1, IGF2 and TGFB1 was also observed, interleukin 1 receptor being always strongly expressed in steatohepatitis linked to alcohol or obesity. In conclusion, mitochondrial alterations play a major role in the development of steatosis per se. Activation of inflammatory pathways is present at a very early stage of steatosis, even if no morphological sign of inflammation is observed.

Soy isoflavones, body composition, and physical performance

OBJECTIVES

Physiologic changes, occurring during the process of aging, can have serious health consequences, such as increased risk of chronic disease and disability. Decline in estradiol levels after menopause is hypothesized to contribute to this risk. Thus, hormone therapy (HT) might prevent or delay those changes. However, HT has serious side effects and alternative approaches are needed.

METHODS

We performed a 12-month double-blind randomized trial comparing soy protein containing 99mg isoflavones (aglycone weights) with milk protein (placebo) daily in 202 postmenopausal women aged 60-75 years. Endpoints were body composition, and physical performance. Randomization resulted in reasonable well-balanced groups, 153 (76%) women completed the trial. Compliance was good (plasma genistein levels 55 +/- 101 and 1259 +/- 1610 nmol/L for placebo and soy group, respectively). The changes in the endpoints during the intervention period among the two intervention groups were analyzed.

RESULTS

Body mass index (BMI) and waist-to-hip ratio did not change during intervention. Handgrip strength at the final visit was slightly worse in the soy group compared to the placebo group (-0.45 kg (95% C.I.: -2.5, 1.6 kg; p = 0.7), but this difference was not statistically significant. Self-reported functional status, mobility and physical performance, all slightly improved during intervention but there were no differences between the groups.

CONCLUSIONS

The results of the present trial do not support the view that soy isoflavones have favorable effects on body composition and physical performance in postmenopausal women.

Height and body mass index in relation to colorectal and gallbladder cancer in two million Norwegian men and women

OBJECTIVES

The present study aimed at exploring the relations between BMI and stature and colorectal and gallbladder cancer in a huge Norwegian cohort with measured height and weight.

MATERIAL AND METHODS

Height and weight were measured in two million Norwegian men and women aged 20-74 during 1963-2001. During follow-up, 47,117 colorectal and 1715 gallbladder cancer cases were registered. Relative risks (RRs) of colorectal and gallbladder cancer were estimated using Cox proportional hazards regression.

RESULTS

The risk of colon cancer increased with increasing BMI in men; the RR of colon cancer per unit increase in BMI was 1.04 (95% CI: 1.04-1.05). For mucinous colorectal adenocarcinomas, the risk increased to a larger extent with increasing BMI in both sexes. The RR of colorectal cancer associated with 10 cm increase in height was 1.14 (95% CI: 1.11-1.16) in men and 1.17 (95% CI: 1.14-1.20) in women. The risk of gallbladder cancer increased with increasing BMI in women; the overall RR associated with one unit increase in BMI was 1.06 (95% CI: 1.04-1.07). There was no association between height and gallbladder cancer in either sex.

CONCLUSION

The risk of colon cancer increased with increasing BMI in men, and the risk of gallbladder cancer increased with increasing BMI in women. In both sexes, the risk of colon cancer increased with increasing height.

Body size in relation to cancer of the uterine corpus in 1 million Norwegian women

A positive association between overweight/obesity and endometrial cancer has been observed. It has been hypothesized that obesity is mostly associated with a subtype described as estrogen-dependent (Type I tumors), constituting about 80% of the endometrial tumors. Few epidemiologic studies have, however, analyzed different histological subtypes separately. The present study aimed at exploring the relations between body size and histological subtypes of cancer of the uterine corpus. Height and weight were measured in over 1 million Norwegian women aged 20-74 during 1963-2001. During follow-up, 9,227 cancers of the uterine corpus were diagnosed. The tumors were classified as Type I tumors (mostly endometrial adenocarcinomas with subgroups), Type II tumors (papillary, serous, and clear cell adenocarcinomas and some poorly differentiated carcinomas), sarcomas, and mixed tumors. Relative risks (RRs) of cancer of the uterine corpus were estimated using Cox proportional hazards regression. Compared with women with normal BMI, overweight and obese women had an overall RR of cancer of the uterine corpus of 1.36 (95% CI: 1.29-1.42) and 2.51 (95% CI: 2.83-2.66). The increase in risk was most pronounced for Type I tumors, but was also seen for Type II tumors, sarcomas and mixed tumors. The overall RR of corpus uteri cancer associated with a 10-cm increase in height was 1.09 (95% CI: 1.05-1.13), and was mostly observed for Type I tumors.

Obesity: America’s Epidemic

The health risks of overweight and obesity have been well documented. For example, even a 15-lb. weight gain increases a person's risk of diabetes by 50%. In turn, losing as little as 11 lbs. can reduce a person's risk of diabetes by the same percentage. Why, then, aren't more Americans losing weight? This article explores the rising incidence of overweight and obesity in the United States, the reasons so many people fail to lose weight or maintain a weight loss, and the potential for nurses to turn the tide on this epidemic.

Effect of obesity on survival in epithelial ovarian cancer

BACKGROUND

Epidemiologic studies suggest that obese women are more likely to die of ovarian cancer than those of ideal body weight, but it is not known whether increased incidence, comorbidities common to obese women, or altered tumor biology is responsible for this difference. The current study attempted to determine the influence of excess body weight on ovarian cancer survival, disease progression, and clinicopathologic factors.

METHODS

The records of patients undergoing surgery for epithelial ovarian cancer at Cedars Sinai Medical Center between January 1, 1996 and June 30, 2003 were reviewed for height, weight, age, comorbidities, and treatment-specific details. Statistical analyses included the Fisher exact test, Kaplan-Meier survival, and Cox regression analyses.

RESULTS

In all, 216 patients were identified. Eight percent were underweight (body mass index [BMI] < 18.5), 50% were ideal body weight (18.5 </= BMI < 25), 25% were overweight (25 </= BMI < 30), and 16% were obese (BMI >/= 30). Age, comorbidities including coronary artery disease and venous thromboembolism, and rates of optimal surgical cytoreduction were similar among BMI strata. Diabetes and hypertension were more common in obese women. Ten (29%) of the obese patients had International Federation of Gynecology and Obstetrics (FIGO) Stage I disease, compared with 19 (10%) of the patients with BMI < 30 (P = .01). In a subcohort of 149 patients with Stage III or IV disease, a significant trend was identified favoring increased BMI as an independent negative factor for disease-free (P = .02) and overall (P = .02) survival.

CONCLUSIONS

Obese patients were more likely to have disease limited to the ovaries. For patients with advanced stage disease, obesity was independently associated with both shorter time to recurrence and shorter overall survival. These findings suggest an effect of excess body weight on tumor biology, and studies are under way to elucidate the molecular and hormonal mechanisms underlying these clinical observations.

Relationships between familial risks of cancer and the effects of heritable genes and their SNP variants

Familial risks for cancer can be used in many ways in guiding gene identification efforts and, more broadly, in understanding cancer etiology. Gene identification efforts may be properly designed and targeted if the familial risks are well characterized and the mode of inheritance is identified. Single nucleotide polymorphisms (SNPs) are extensively used in case-control studies of practically all cancer types. They are used for the identification of inherited cancer susceptibility genes and those that may interact with environmental factors. However, being genetic markers, they are applicable only on heritable conditions, which is often a neglected fact. Based on the data in the nationwide Swedish Family-Cancer Database, we review familial risks for all main cancers and discuss the evidence for a heritable component in cancer. The available evidence, including differences in cancer incidence between regions and temporal changes within regions, indicates that cancer is mainly an environmental disease, with a minor heritable etiology. The large environmental component will hamper the success of SNP-based genetic association studies. Empirical familial risks should be used to evaluate the feasibility of such studies. We develop figures for the assessment of genetic parameters based on familial risks. Such data are helpful in the estimation of the expected genetic effects in cancer. Overall, we consider the likelihood of a successful application of SNPs in gene-environment studies small, unless established environmental risk factors are tested on proven candidate genes.

Physical activity, obesity, energy intake, and the risk of non-Hodgkin's lymphoma: a population-based case-control study

The authors conducted a population-based case-control study of 1,030 cases with histologically confirmed, incident non-Hodgkin's lymphoma (NHL) and 3,106 controls to assess the impact of recreational physical activity, obesity, and energy intake on NHL risk in Canada from 1994 to 1997. Compared with those for subjects in the lowest quartiles of total recreational physical activity, multivariable-adjusted odds ratios for subjects in the highest quartile were 0.79 (95% confidence interval (CI): 0.59, 1.05) for men and 0.59 (95% CI: 0.42, 0.81) for women. Obesity (body mass index > or = 30 kg/m2) was associated with odds ratios of 1.59 (95% CI: 1.18, 2.12) for men and 1.36 (95% CI: 1.00, 1.84) for women. For men and women with a lifetime maximum body mass index of > or = 30 kg/m2, respective odds ratios were 1.55 (95% CI: 1.16, 2.06) and 1.10 (95% CI: 0.83, 1.46). For men and women in the highest quartiles of calorie intake, respective odds ratios were 1.95 (95% CI: 1.45, 2.62) and 1.13 (95% CI: 0.84, 1.52). Some differences were found between histologic subtypes of NHL for these associations. This study suggests that recreational physical activity decreases NHL risk, while obesity and excess calorie intake increase it. More studies are needed to confirm these results, especially the differences between histologic subtypes.

Lifestyle factors and the risk of adult leukemia in Canada

OBJECTIVES

To evaluate the impact of active smoking, obesity, and dietary intakes on the risk of adult leukemia.

METHODS

We analysed data obtained from a population-based case-control study conducted in eight Canadian provinces. Risk estimates were generated by applying multivariate logistic regression methods to 1068 incident histologically confirmed leukemia cases and 5039 controls aged 20-74.

RESULTS

We found a statistically significant increased risk for acute myeloid leukemia (AML) associated with active smoking, with a clear dose-response relationship and an adjusted odds ratio (OR) of 1.5 (95% confidence interval [CI]=1.1-2.0) for heavy smokers reporting more than 20 pack-years of cigarette smoking. We also observed positive associations with the highest body mass index (BMI) for AML, chronic myeloid leukemia, and chronic lymphoid leukemia with a significant dose-response relationship. No association with leukemia was observed for the intake of fruits and vegetables, and the effect of active smoking on adult leukemia risk was not modified by fruits and/or vegetables consumption or obesity. However, the positive risk for AML associated with active smoking disappeared among subjects with high BMI (> or =30 kg/m2).

CONCLUSIONS

Our study contributes to the accumulating evidence linking AML and active smoking, and provides some evidence that obesity increases the risk of most of the adult leukemia subtypes.

Pathophysiologic changes of obesity

This article builds on the well-known changes that occur with obesity by drawing from recent advances reported in the literature for an improved understanding of obese patients. The dissemination of information regarding the health risks with being overweight or obese to both the public and the health care community are widespread and effective from a public health perspective. The mechanisms underlying these associated risks must continue to be explored for physicians' knowledge to truly increase, and lead to advances in our understanding of the pathophysiology of obesity.

Height and body mass index in relation to cancer of the small intestine in two million Norwegian men and women

The present study aimed at exploring the relations between body mass index (BMI, (weight in kilograms)/(height in meters)(2)) and stature and cancer of the small intestine (1162 cases) in a large Norwegian cohort (of two million) with measured height and weight. Elevated BMI in males and increasing height in both sexes were associated with a moderately increased risk of cancer of the small intestine.

Comparison of self-reported height and weight by cancer type among men from Montreal, Canada

Among men there is epidemiological evidence for an association between obesity and increased risk of renal cell carcinoma, colon cancer and adenocarcinoma of the oesophagus. The evidence for other cancer sites remains inconsistent. We conducted a large population-based, multi-site, case-control study of environmental causes of cancer among males in Montreal, Canada. Among the many questionnaire items collected by interview were height and usual weight. We compared height, weight and body mass index (BMI) among individuals with 11 different cancer types (combined N=3016) and population-based controls (N=509). Linear regression was used to model the relationship of the disease status with each of three dependent continuous variables (height, weight and BMI), while adjusting for covariates. For most cancer groups, weight and BMI were lower than among population controls. Because of potential information bias and reverse causality bias, we focused on the comparisons among cancer types. The lowest BMI values were observed among men with squamous cell carcinoma of the oesophagus, lung and stomach cancers. The highest BMIs were reported by men with prostate and kidney cancers, and oesophageal adenocarcinoma. Inconsistencies in the epidemiological literature on obesity and cancer risk could be related to the difficulties in obtaining unbiased reports of pre-disease weight and to publication bias.

Energy intake, meal frequency, and health: a neurobiological perspective

The size and frequency of meals are fundamental aspects of nutrition that can have profound effects on the health and longevity of laboratory animals. In humans, excessive energy intake is associated with increased incidence of cardiovascular disease, diabetes, and certain cancers and is a major cause of disability and death in industrialized countries. On the other hand, the influence of meal frequency on human health and longevity is unclear. Both caloric (energy) restriction (CR) and reduced meal frequency/intermittent fasting can suppress the development of various diseases and can increase life span in rodents by mechanisms involving reduced oxidative damage and increased stress resistance. Many of the beneficial effects of CR and fasting appear to be mediated by the nervous system. For example, intermittent fasting results in increased production of brain-derived neurotrophic factor (BDNF), which increases the resistance of neurons in the brain to dysfunction and degeneration in animal models of neurodegenerative disorders; BDNF signaling may also mediate beneficial effects of intermittent fasting on glucose regulation and cardiovascular function. A better understanding of the neurobiological mechanisms by which meal size and frequency affect human health may lead to novel approaches for disease prevention and treatment.

Endometrial cancer: Population attributable risks from reproductive, familial and socioeconomic factors

In this study, based on the Swedish Family-Cancer Database, risk factors and their population attributable fractions (PAFs) for endometrial cancer were studied. Over 700,000 women at ages 51-68 years, accumulating 23 million person-years at risk, were entered into Poisson analysis. Overall, reproductive factors (parity and age at last birth) showed a relative risk (RR) of 1.91 and a PAF of 45.51% when the reference group was women with a parity of 3+ and the last childbirth at ages over 34 years. The RR for family history was 2.33 but the PAF was only 2.09%. The RR for socioeconomic factors was a modest 1.12 but the PAF was 6.34%. The combined PAF of these three types of risk factors was 51.84%. Although the present analysis lacked data on some important risk factors for endometrial cancer, the results suggest that a large proportion of the etiology of endometrial cancer can be defined by known epidemiological risk factors.

Effects of excess weight on cancer incidences depending on cancer sites and histologic findings among men: Korea National Health Insurance Corporation Study

PURPOSE

The effects of excess weight on the development of cancers are controversial, and little is known for populations outside the United States and Europe. We conducted this study to assess the effects of excess weight with a large cohort of Koreans.

METHODS

We assessed the relationship between body mass index (BMI) and various cancers in a 10-year follow-up cohort of 781,283 Korean men who were free of prior cancer at baseline. Weight and height were measured, and questionnaires related to health behaviors and medical history were completed. Data on newly developed cancers were obtained from two organizations in Korea. A proportional hazards model was used to examine the relationship between BMI and cancer.

RESULTS

Adenocarcinoma in the colon and rectosigmoid, hepatocellular carcinoma, cholangiocarcinoma, adenocarcinoma in the prostate, renal cell carcinoma, papillary carcinoma in the thyroid, small-cell carcinoma in the lung, non-Hodgkin's lymphoma, and melanoma had positive dose-dependent relationships with BMI (all P < .05). Although no linear trend was found (P = .267), obese men who never smoked with a BMI of >or= 30 kg/m(2) had an increased risk of developing gastric adenocarcinoma (relative risk = 1.73). Other cancers, such as leukemia, multiple myeloma, and gallbladder and pancreatic cancer, did not show significant associations.

CONCLUSION

These findings show that, even in Koreans, obesity clearly increases the risk of many types of cancers and the strength of the associations varies with the organ and histologic type. Because these obesity-related cancers are reported to be rapidly increasing in Korea and many other Asian countries, controlling obesity epidemics could be an effective tool for preventing these cancers in these areas.

Body weight and body mass index and ovarian cancer risk: A case-control study in China

OBJECTIVE

To investigate the association between ovarian cancer risk and body height, weight, and BMI.

METHODS

A hospital-based case-control study was conducted in China from 1999 to 2000. The study sample included 254 cases with histologically confirmed epithelial ovarian cancer and 652 controls. Information of adult height and weight at diagnosis, at 5 years before diagnosis and at age 21 years, was collected by face-to-face interview using a structured questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using unconditional logistic regression analyses.

RESULTS

The ovarian cancer risk was significantly increased with higher body weight and BMI at 5 years before diagnosis, but not at diagnosis nor at age 21 years. The adjusted ORs were 1.67 (95% CI = 1.04-2.67) for body weight >60 kg versus < or =50 kg and 1.75 (95% CI = 1.13-2.72) for BMI > or = 25.0 versus 18.5-21.9 at 5 years before diagnosis. There was no association between body height and ovarian cancer risk.

CONCLUSION

Pre-morbid body weight and BMI were associated with an increased risk of ovarian cancer in Chinese women.

Long-term weight gain prevention: a theoretically based Internet approach

BACKGROUND

A major focus of Healthy People 2010 is promoting weight management and physical activity because overweight, obesity, and a sedentary lifestyle are strongly associated with risk for heart disease and stroke, diabetes, cancers, and premature death.

METHODS

Prevalence data and a focused review of weight management and physical activity studies point to the long-term weight gain prevention in normal weight (21-25 BMI), overweight (25-29 BMI), and even moderate obese (30-34 BMI) people as one alternative to prioritizing weight loss in health behavior interventions. This is because on a population basis annual weight gain is small (approximately 0.8 kg/year) and preventing weight gain appears to require only an energy shift of about 100 cal/day either through a modest increase in physical activity and/or consuming slightly less calories to maintain an energy balance. A more dynamic use of social cognitive theory (SCT) for developing programs to maintain health behavior changes is emerging with some evidence of long-term maintenance. The high use of the Internet provides a vehicle to reach different population segments with readily accessible, SCT-tailored long-term programs. Research studies using the Internet with tailored SCT interventions have shown changes in nutrition practices, physical activity, and weight loss for up to a year.

CONCLUSIONS

One promising approach to weight gain prevention in population segments is the development and wide spread use of longer-term Internet programs using specific principles and procedures from SCT.

Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice

BACKGROUND

Obesity is a common health problem that requires a long-term care approach. We systematically reviewed long-term (> or =2 y) studies investigating dietary/lifestyle, pharmacologic, and surgical weight loss methods to assess (1) weight loss efficacy, defined by absolute weight loss and the proportion of subjects with > or =5% weight loss, (2) effects of weight loss on cardiovascular risk factors, and (3) applicability of findings from studies to everyday clinical practice.

METHODS

The MEDLINE, HealthSTAR, and the Cochrane Controlled Trials databases were searched for studies investigating the long-term efficacy of weight loss methods in overweight and obese adults. Data were extracted for (i) weight loss after 1 y (pharmacologic studies only), 2 y, 3 y, and 4 y, (ii) proportion of subjects with > or =5% weight loss at the end of follow-up, and (iii) changes (end-of follow-up minus baseline values) in blood lipids, fasting blood glucose, and systolic and diastolic blood pressure.

RESULTS

Dietary/lifestyle therapy provides <5 kg weight loss after 2-4 y, pharmacologic therapy provides 5-10 kg weight loss after 1-2 y, and surgical therapy provides 25-75 kg weight loss after 2-4 y. Weight loss of > or =5% baseline weight is not consistently associated with improvements in cardiovascular risk factors and these benefits appear to be intervention specific and occur mainly in people with concomitant cardiovascular risk factors. Weight loss studies have methodologic limitations that restrict the applicability of findings to unselected obese people assessed in everyday clinical practice. These limitations include an inadequate study duration, large proportions of subjects lost to follow-up, a lack of an appropriate usual care group, and a lack of reporting of outcomes in high-risk subgroups.

CONCLUSIONS

Dietary/lifestyle and pharmacologic weight loss interventions provide modest weight loss, and may improve markers of cardiovascular risk factors although these benefits occur mainly in patients with cardiovascular risks. Studies investigating weight loss have methodologic limitations that restrict the applicability of findings to obese patients assessed in clinical practice.

Obesity and risk of nonfatal unintentional injuries

BACKGROUND

Obesity is recognized as a risk factor for multiple chronic diseases. Yet, it is unclear whether obesity is also associated with an increased risk of nonfatal unintentional injury.

METHODS

A population-based survey was conducted among adults aged > or = 18 years from January 1999 through October 2000. The relationship was investigated between body mass index (BMI), defined as weight in kilograms divided by the square of the height in meters (kg/m2), and risk of nonfatal unintentional injuries among 2575 respondents aged > or = 20 years by comparing percentage of adults between obese and nonobese respondents who had injuries. Multivariate logistic regression further examined this relationship by controlling for confounding demographics.

RESULTS

A total of 370 respondents reported injuries in the previous year. We observed a linear dose-response trend among women. An estimated 7.0% of underweight individuals (BMI <18.5) reported injuries. In contrast, 26.0% of men and 21.7% of women with a BMI > or = 35.0 reported injuries. The odds ratio of injuries for individuals with a BMI > or = 35.0 was 2.00 (95% confidence interval=1.07-3.74, p<0.05) after controlling for gender, age, education level, marital status, family poverty status, and area of residence.

CONCLUSIONS

A marginally significant association between extreme obesity and elevated risk of injuries was observed. Efforts to promote optimal body weight may reduce not only the risk of chronic diseases but also the risk of unintentional injury among overweight and obese individuals.

Obesity and overweight in relation to organ-specific cancer mortality in London (UK): findings from the original Whitehall study

OBJECTIVE

To examine the relation of obesity and overweight with organ-specific cancer mortality.

METHODS

In the Whitehall prospective cohort study of London-based government employees, 18 403 middle-age men participated in a medical examination between 1967 and 1970. Subjects were followed up for cause-specific mortality for up to 35 y (median: interquartile range (25th-75th centile); 28.1 y: 18.6-33.8).

RESULTS

There were over 3000 cancer deaths in this cohort. There was a raised risk of mortality from carcinoma of the rectum, bladder, colon, and liver, and for lymphoma in obese or overweight men following adjustment for range of covariates, which included socioeconomic position and physical activity. These relationships held after exclusion of deaths occurring in the first 20 y of follow-up.

CONCLUSION

Avoidance of obesity and overweight in adult life may reduce the risk of developing some cancers.

ADVANCES IN CANCER EPIDEMIOLOGY: Understanding Causal Mechanisms and the Evidence for Implementing Interventions

In a worldwide population of 6 billion, in the year 2000, approximately 10 million cancers were diagnosed, and there were an estimated 6.2 million cancer deaths. Whereas the universality of cancer incidence and mortality is established, the burden of cancer by type or organ site is distributed unequally between developing and industrialized nations. Populations in developing countries are disproportionately affected by cancers in which infectious agents are causal. Our review of advances in cancer epidemiology underscores the complexity of pathogenic mechanisms mediated by chronic inflammation, obesity, and gene-environment interactions as in tobacco and alcohol carcinogenesis. Ultimately, the implementation of effective cancer control interventions that will serve to alleviate the cancer burden must integrate basic and applied research in the behavioral, social, biomedical, and population sciences.

Obesity and awareness of obesity as risk factors for breast cancer in six ethnic groups

OBJECTIVE

To document BMI and knowledge regarding obesity as a risk factor for breast cancer among subpopulations of African-, Caribbean-, and European-American women and to consider the variables predicting obesity in these diverse groups.

RESEARCH METHODS AND PROCEDURES

A stratified cluster-sampling plan was used to recruit 1364 older women from Brooklyn, NY, during 2000-2002. Two groups were born in the United States (African Americans and European Americans), whereas others were from the English-speaking Caribbean, Haiti, the Dominican Republic, and Eastern Europe. Participants provided demographics, height and weight measures, and estimates of the risk obesity posed for breast cancer.

RESULTS

Women from all groups were significantly overweight (BMI > 25 kg/m(2)), although European Americans were lowest, followed by Dominicans and Haitians; African-American and English-speaking Caribbean women fell into the obese range, even when background variables were controlled. Knowledge of obesity as a breast cancer risk factor was also poor across groups, but Dominicans and Haitians had the lowest scores on knowledge. Importantly, knowledge was not associated with BMI in the overall sample, even when controlling for demographics and ethnicity, although logistic regressions comparing normal weight women with overweight and obese groupings suggested some knowledge of breast cancer risk in the overweight, but not the obese, group.

DISCUSSION

The findings remind health professionals of the need to consider more specific ethnic groupings than has hitherto been the case, as well as consider how ethnic and cultural variables may influence perceptions of obesity and its relation to cancer risk.

Increased 2-hydroxylation of estrogen in women with a family history of osteoporosis

Recent studies indicate that women with predominant estrogen metabolism through the 2-hydroxyl (inactive) pathway have lower bone mineral density (BMD) compared with those with predominant 16alpha-hydroxylation (active). Although many factors have been identified to affect estrogen metabolism, the role of a family history of osteoporosis remains unknown. The objective of this study was to investigate the influence of family history of osteoporosis and other clinical factors on estrogen hydroxylation. This was a cross-sectional study conducted in a university-based research center from May 2002 to February 2004. The participants included 175 otherwise healthy postmenopausal women at least 1 yr from the last menstrual period. Main outcome measures were urinary estrogen metabolites and BMD of the spine and femur. Women with a family history of osteoporosis had significantly higher log-transformed ratios of 2-hydroxyestrone/16alpha-hydroxyestrone (0.303 +/- 0.03 vs. 0.226 +/- 0.03; P = 0.04) and 2-methoxyestrone/16alpha-hydroxyestrone (0.024 +/- 0.02 vs. -0.036 +/- 0.02; P = 0.03) compared with women without family history. As expected, these women also had significantly lower BMD at the total femur, trochanter, and intertrochanter. Surprisingly, calcium intake positively correlated with metabolite levels, and women in the highest quartile of calcium intake had the highest levels of urinary metabolites. In conclusion, women with a positive family history of osteoporosis have predominant estrogen metabolism through the inactive 2-hydroxyl pathway; thus, the increased risk of osteoporosis in those with family history may in part be related to inherited differences in estrogen metabolism. The finding that calcium intake modulates estrogen hydroxylation has never been reported and thus deserves additional investigation.

Diet and colorectal cancer: implications for the obese and devotees of the Atkins diet

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the Western world and its prevalence is increasing. Potential causes of this increase are changes in diet and the increases in obesity seen. This paper looks at the literature surrounding diet and obesity and the links to this increase in CRC. Heralded as a weight loss miracle we investigate whether the literature suggests the Atkins diet may actually do more harm than good by acting to increase an individual's risk of CRC. Obesity has been demonstrated to be a major factor in the increase in CRC although links to changes in diet are more tenuous. Published studies on diet suggest the Atkins diet may help reduce rather than increase the risk of CRC.

Body Mass Index and Risk of Malignant Lymphoma in Scandinavian Men and Women

BACKGROUND

The incidence of non-Hodgkin lymphoma and prevalence of obesity are increasing globally. A suggested positive association between obesity and risk of non-Hodgkin lymphoma has prompted us to investigate the relationship between body mass index (BMI) and risk of malignant lymphoma subtypes in a population-based case-control study.

METHODS

Telephone interviews were conducted with 3055 case patients with non-Hodgkin lymphoma and 618 case patients with Hodgkin lymphoma diagnosed between October 1, 1999, and August 30, 2002, and 3187 population-based control subjects. The interviews assessed current height, normal adult weight, and other possible risk factors. Multivariable odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for risk of lymphoma were estimated by unconditional logistic regression. All statistical tests were two-sided.

RESULTS

BMI was not associated with risk of overall non-Hodgkin lymphoma or of Hodgkin lymphoma (for example, comparing the highly obese group [BMI > or =35.0 kg/m2] with the normal-weight group [BMI = 18.5-24.9 kg/m2], OR for risk of non-Hodgkin lymphoma = 0.9, 95% CI = 0.6 to 1.3; P(trend) across all categories of BMI = .27). BMI was also not associated with risk of any non-Hodgkin lymphoma subtype evaluated, although there was some evidence of a positive association with risk of diffuse large B-cell lymphoma (for example, comparing the highly obese group with the normal-weight group, OR for diffuse large B-cell lymphoma = 1.5, 95% CI = 0.9 to 2.4; P(trend) =.05).

CONCLUSIONS

Excess weight does not appear to be associated with an increased risk of malignant lymphoma in general, or with a risk of most major lymphoma subtypes. Hence, the growing incidence of obesity is unlikely to be an important contributor to the increasing incidence of non-Hodgkin lymphoma worldwide.

Impact of morbid obesity on medical expenditures in adults

CONTEXT

Morbid obesity (body mass index (BMI) > or =40 kg/m2) is associated with substantially increased morbidity and mortality from chronic health conditions and with poorer health-related quality of life; however, less is known about the impact of morbid obesity on healthcare expenditures.

OBJECTIVE

To examine the impact of morbid obesity on healthcare expenditures using a nationally representative sample of US adults.

DESIGN, SETTING, AND PARTICIPANTS

We performed a cross-sectional analysis of 16 262 adults from the 2000 Medical Expenditure Panel Survey, a nationally representative survey of the noninstitutionalized civilian population of the United States. Per capita healthcare expenditures were calculated for National Institutes of Health BMI categories, based on self-reported height and weight, using a two-part, multivariable model adjusted for age, gender, race, income, education level, type of health insurance, marital status, and smoking status.

MAIN OUTCOME MEASURES

Odds of incurring any healthcare expenditure and per capita healthcare expenditures associated with morbid obesity in 2000.

RESULTS

When compared with normal-weight adults, the odds of incurring any healthcare expenditure in 2000 were two-fold greater among adults with morbid obesity. Per capita healthcare expenditures for morbidly obese adults were 81% (95% confidence interval (CI): 48-121%) greater than normal-weight adults, 65% (95% CI: 37-110%) greater than overweight adults, and 47% (95% CI: 11-96%) greater than adults with class I obesity. Excess costs among morbidly obese adults resulted from greater expenditures for office-based visits, outpatient hospital care, in-patient care, and prescription drugs. Aggregate US healthcare expenditures associated with excess body weight among morbidly obese US adults exceeded $11 billion in 2000.

CONCLUSIONS

The economic burden of morbid obesity among US adults is substantial. Further research is needed to identify interventions to reduce the incidence and prevalence of morbid obesity and improve the health and economic outcomes of morbidly obese adults.

Abdominal obesity, insulin resistance, and colon carcinogenesis are increased in mutant mice lacking gastrin gene expression

BACKGROUND

The authors recently reported that gastrin gene knockout (GAS-KO) mice had an increased risk for colon carcinogenesis in response to azoxymethane (AOM) compared with their wild type (WT) littermates. In the current report, the authors discuss the predisposition of GAS-KO mice to develop obesity and metabolic hormonal changes that may contribute to their increased risk of colon carcinogenesis.

METHODS

The weight and deposition of fat was monitored in the mice over a 14 month period, using magnetic resonance imaging and nuclear magnetic resonance techniques. Changes in plasma concentrations of ghrelin, leptin, insulin, and glucose were assessed using radioimmunoassay analysis and enzyme-linked immunosorbent assays. Preneoplastic markers of colon carcinogenesis (aberrant crypt foci [ACFs]), in response to AOM, were measured in a subset of obese versus lean GAS-KO mice and were compared with the markers in WT mice.

RESULTS

Increases in visceral adiposity were evident by age 2 months in GAS-KO mice, resulting in macroscopic obesity by age 7 months. Hyperinsulinemia and insulin:glucose ratios were increased significantly in GAS-KO mice as young as 1 month and preceded alterations in nonfasting leptin and ghrelin levels. The number of ACFs per mouse colon were increased significantly in the following order: obese GAS-KO mice > lean GAS-KO mice > WT mice. Fasting plasma insulin levels were 0.88 +/- 0.1 ng/mL, 1.45 +/- 0.3, and 2.76 +/- 0.9 ng/mL in the WT, GAS-KO lean, and GAS-KO obese mice, respectively.

CONCLUSIONS

The current results suggest the novel possibility that loss of amidated gastrins may increase adipogenesis, hyperinsulinemia, and colon carcinogenesis in GAS-KO mice. The increase in colon carcinogenesis may be due in part to hyperinsulinemia, increased obesity, and other associated hormone changes that were measured in GAS-KO mice.

Is there an association between maternal weight and the risk of testicular cancer? An epidemiologic study of Norwegian data with emphasis on World War II

Since registration started in the 1950s, the incidence of testicular cancer (TC) in the Western world has increased, which is also the case in Norway. Men born in Norway during World War II (WWII), however, have a lower TC incidence than men born in the years before or after WWII. Increased fetal exposure to estrogen during the first trimester of pregnancy has been proposed as a risk factor for the development of TC later in life. Increased maternal weight is associated with higher insulin levels, leading to lower sex hormone-binding globulin levels and thereby increased levels of bioavailable estrogens for transplacental transfer from mother to fetus. The aim of the present study was therefore to examine whether there was an association between maternal weight and the incidence of TC among those who were born in a time period where the nutritional conditions changed, i.e., around the time of WWII. We compared data for a random sample of women giving birth in Oslo, Norway, in the years 1931 to 1955 with the TC incidence among men born in the whole country in the same time period. Maternal weight at delivery was used as a proxy for first-trimester weight. We found a correlation (Spearman's rho = 1.00, p < 0.01; Pearson's r = 0.95, p = 0.02) between the TC incidence and maternal weight adjusted for birth weight and maternal age. Although one cannot draw firm conclusions from ecologic correlations, these findings suggest that the increase in TC incidence over the past decades could be at least partly attributed to the increased maternal body weight observed in most populations in the relevant time period since TC is thought to be associated with in utero conditions.

Urinary estrogen metabolites, prostate specific antigen, and body mass index among African–American men in South Carolina

INTRODUCTION

Estrogen metabolites have been linked to risk of breast cancer, and we were interested in whether they are associated with prostate specific antigen (PSA) and other factors associated with prostate cancer. African-American (AA) men in South Carolina have among the highest prostate cancer rates in the world, and thus provide an ideal population in which to investigate this hypothesis.

METHODS

We recruited AA men attending prostate cancer screenings in and around Columbia, South Carolina. Because very few men had elevated PSAs, we restricted our study to the 77 men whose PSA was below the cutpoint used by the screening program to indicate need for diagnostic workup. These men provided spot urine samples and answered demographic and lifestyle questions including self-reported body weight, height, exercise, tobacco use, medications, cancer history and age. Levels of urinary 2-hydroxyestrone (2-OHE1) and 16alpha-hydroxyestrone (16alpha-OHE1), and their ratio (2/16) and blood PSA levels were determined.

RESULTS

After adjusting for a statistically significant interaction between age and BMI, we found a reduction of 14.2% in 2-OHE1 for each 1.0 ng/ml increase in PSA (p=0.05). For obese AA men only (BMI> or =30 kg/m2), 2-OHE1 increased by 36% for each decade of age (p=0.009).

CONCLUSIONS

Estrogen metabolites may be related to PSA level in AA men. Older men with BMIs greater than 30 kg/m2 had an unexpected increase in 2-OHE1, suggesting a dysregulation of this estrogen metabolism pathway. Further studies of estrogen metabolites may provide insights into prostate cancer risk factors.

Obesity and risk of cancer in Japan

We conducted a population-based prospective cohort study in Japan to examine the relationship between body mass index (BMI) and the risk of incidence of any cancer and of cancer at individual sites. Body mass index was calculated from self-administered body weight and height at baseline. Relative risks (RR) and 95% confidence intervals (CI) were calculated in multivariate proportional-hazards models. Among 27,539 persons (15,054 women and 12,485 men) aged 40 years or older who were free of cancer at enrollment in 1984, 1,672 (668 women and 1,004 men) developed cancer during 9 years of follow-up. In women, after adjustment for potential confounders, the RR of all cancers associated with different BMI, relative to a BMI of 18.5-24.9, were 1.04 (95% CI = 0.85-1.27) for BMI = 25.0-27.4, 1.29 (1.00-1.68) for BMI = 27.5-29.9 and 1.47 (1.06-2.05) for BMI >/=30.0 (p for trend = 0.007). Higher BMI was also significantly associated with higher risk of cancers of the colorectum, breast (postmenopausal), endometrium and gallbladder in women. In men, we observed significantly increased all-cancer risk among only never-smokers. Overweight and obesity could account for 4.5% (all subjects) or 6.2% (never-smokers) of the risk of any cancer in women and -0.2% (all subjects) or 3.7% (never-smokers) in men. The value for women was within the range among women reported from Western populations (3.2%-8.8%). Our data demonstrate that excess weight is a major cancer risk among Japanese women.

Body Mass Index and Risk of Leukemia in Older Women

Overweight [body mass index (BMI) 25.0-29.9 kg/m2] and obesity (BMI ≥30 kg/m2) are risk factors for several malignancies. The Iowa Women's Health Study was examined to determine whether increased BMI was associated with leukemia development. Over 40,000 Iowa women (ages 55-69 years) completed a self-administered lifestyle and health questionnaire in 1986 that included current height and weight. Two hundred women developed leukemia during the period 1986 to 2001 including 74 acute myelogenous leukemia (AML) and 88 chronic lymphocytic leukemia. The risk of AML was increased among women who reported being overweight or obese (relative risk, 1.9; 95% confidence interval, 1.0-3.4; relative risk, 2.4; 95% confidence interval, 1.3-4.5; Ptrend = 0.006) compared with women of normal weight. There was little evidence of a positive association for chronic lymphocytic leukemia (Ptrend = 0.6). Given the prevalence of overweight and obesity in the United States, the population attributable risk of AML due to obesity could approach 30%.

The effect of CYP19 and COMT polymorphisms on exercise-induced fat loss in postmenopausal women

OBJECTIVE

To examine whether genetic polymorphisms in CYP19 [intron 4 (TTTA)n; n = 7 to 13 and a 3-base pair deletion, which is in strong linkage disequilibrium with the seven repeat] and COMT (Val108/158Met) modified the change in BMI, total and percentage body fat, or subcutaneous and intra-abdominal fat during a year-long exercise intervention trial. These genes metabolize estrogens and androgens, which are important in body fat regulation.

RESEARCH METHODS AND PROCEDURES

A randomized intervention trial was used, with an intervention goal of 225 min/wk of moderate-intensity exercise for one year. Participants (n = 173) were postmenopausal, 50 to 75 years old, sedentary, overweight or obese, and not taking hormone therapy at baseline.

RESULTS

Exercisers with two vs. no CYP19 11-repeat alleles had a larger decrease in total fat (-3.1 kg vs. -0.5 kg, respectively, p = 0.01) and percentage body fat (-2.4% vs. -0.6%, respectively, p = 0.001). Exercisers with the COMT Met/Met vs. Val/Val genotype had a smaller decrease in percentage fat (-0.7% vs. -1.9%, respectively, p = 0.05). Among exercisers, women with the COMT Val/Val genotype and at least one copy of the CYP19 11-repeat allele vs. those with neither genotype/allele had a significantly larger decrease in BMI (-1.0 vs. +0.1 kg/m2, respectively, p = 0.009), total fat (-2.9 vs. -0.5 kg, respectively, p = 0.004), and percentage body fat (-2.6% vs. -0.4%, respectively, p < 0.001).

DISCUSSION

Genetic polymorphisms in CYP19 and COMT may be important for body fat regulation and possibly modify the effect of exercise on fat loss in postmenopausal women.

Somatostatin and cancer: applying endocrinology to oncology

Somatostatin is a peptide hormone that normally suppresses growth hormone (GH), thyrotropin (TSH), insulin and gut hormone release, as well as affecting multiple aspects of gastrointestinal function. It achieves these pleiotropic effects by binding somatostatin receptors (SSTR), a family of five G-protein coupled membrane receptors. Somatostatin analogs, such as octreotide, lanreotide and vapreotide, are well-established treatments for tumors that over secrete these hormones. Recently, use of somatostatin analogs for treating nonendocrine malignancies are being explored. Hu et al. found progressive reduction in SSTR3 expression when comparing normal gastric mucosa versus well differentiated versus poorly differentiated gastric adenocarcinomas; octreotide inhibited growth and induced apoptosis in vitro of those cells expressing SSTR3. Potential mechanisms by which somatostatin analogs may be useful in oncology include its endocrine actions, autocrine/paracrine effects, SSTR-mediated cell signaling and SSTR-mediated cell labeling.

Female gender and wealth are associated to overweight among adolescents in La Paz, Bolivia

OBJECTIVE

To describe the prevalence of overweight, obesity and being thin in adolescents of La Paz City, Bolivia.

DESIGN

Cross-sectional study, clustered sampling.

SETTING

La Paz, Bolivia, August-September 2003.

SUBJECTS

Height and weight of 525 adolescents (mean age 16 y; s.d.+/-1.3) attending public and private schools were measured; sociodemographic characteristics were assessed with a short questionnaire.

RESULTS

The present study reveals that 9.3% (+/-2.5) of the sample are thin adolescents; 19.8% (+/-3.4) is the overall prevalence of overweight and 2.3% (+/-1.3) the overall prevalence of obesity. The odds of being thin were higher among those working (P=0.03) and among those of higher age (P<0.001). The odds of being overweight were higher among female subjects (P<0.001). The odds of being obese were higher among younger adolescents (P=0.046) and among the more wealthy ones (P=0.044).

CONCLUSIONS

A large prevalence of 22% overweight/obesity in adolescents from La Paz City was observed. The findings support the need of enhanced nutritional surveillance and interventions particularly in female adolescents.

Changes in the nutritional status of Bolivian women 1994-1998: demographic and social predictors

INTRODUCTION

Bolivia, as one of the poorest Latin American countries, has dealt with the problems of undernutrition for the last 50 y. Little importance has been given to the increase in overweight and obesity among the population, despite the scientific evidence linking overweight and obesity with mortality and morbidity.

OBJECTIVE

To describe the social and demographic determinants of the nutritional status among women in Bolivia between 1989 and 1998 to gain a better understanding of the nutrition transition phenomena and to identify urgent research needs.

METHODOLOGY

Secondary analysis of the raw data of the Bolivian National Demographic and Health Surveys of 1994 and 1998. Changes in the prevalence of underweight, obesity and overweight are described by sociodemographic characteristics of Bolivian women. Social and demographic determinants of nutritional status have been fitted into a logistic model.

RESULTS

The prevalence of overweight (defined as 25< or =BMI<30 kg/m2) among women of reproductive age (20-44 y) increased by 9 percentage points between 1994 and 1998 (P<0.001), while the prevalence of normal BMI decreased by 10 percentage points (P<0.001). The decrease in the prevalence of underweight (defined as BMI <18.5 kg/m2) from 2.4% in 1994 to less than 1% in 1998 was statistically significant (P<0.001). Obesity (defined as BMI> or =30 kg/m2) was positively associated with geographical region (P=0.001), educational level (P<0.001), age (P=0.003) and total number of children (P=0.001) and negatively associated to rural locality (P=0.001) and native languages (P<0.001). Overweight was inversely associated with rural locality (P=0.013) and with Quechua language (P=0.04), while the total number of children (P<0.001) and year of survey (P<0.001) were positively associated. Underweight decreased dramatically (P<0.001), being positively associated with the region of residence (P=0.04) and inversely associated with the total number of children (P=0.006).

CONCLUSION

The present study suggests that the population of Bolivia is in a transitional stage, with overweight becoming as much of a problem as undernutrition.

Preadipocyte number in omental and subcutaneous adipose tissue of obese individuals

OBJECTIVE

To determine the variation in preadipocyte isolation procedure and to assess the number and function of preadipocytes from subcutaneous and omental adipose tissue of obese individuals.

RESEARCH METHODS AND PROCEDURES

The preadipocyte number per gram of adipose tissue in the abdominal-subcutaneous and abdominal-omental adipose stores of 27 obese subjects with a BMI of 44 +/- 10 kg/m(2) and an age of 40 +/- 9 years was determined.

RESULTS

The assessment of the preadipocyte number was found to be labor intensive and error prone. Our data indicated that the number of stromal vascular cells (SVCs), isolated from the adipose tissue by collagenase digestion, was dependent on the duration of collagenase treatment and the size and the origin of the biopsy. In addition, the fat accumulation and leptin production by differentiated SVCs were dependent on the number of adherent SVCs (aSVCs) in the culture plate and the presence of proteins derived from serum and peroxisome proliferator-activated receptor ligands.

DISCUSSION

Using our standardized isolation and differentiation protocol, we found that the number of SVCs, aSVCs, leptin production, and fat accumulation still varied considerably among individuals. Interestingly, within individuals, the number of SVCs, aSVCs, and the leptin production by differentiating aSVCs from both the subcutaneous and the omental fat depots were associated, whereas fat accumulation was not. In obese to severely obese subjects, differences in BMI and age could not explain differences in SVCs, aSVCs, leptin production, and fat accumulation.

Familial Risk for Colorectal Cancers Are Mainly Due to Heritable Causes

A family history is an identified risk factor for colorectal cancer (CRC). However, it is not known to what extent the risk is due to environmental or heritable genetic factors. We wanted to examine this question for familial CRC adenocarcinoma based on the nationwide Swedish Family-Cancer Database on 10.3 million individuals whose invasive cancers were followed up to year 2000. Standardized incidence ratios (SIRs) for offspring, siblings, and spouses were calculated based on 5-year age, sex, period (10-year bands), area (county), and socioeconomic status standardized rates. A significant risk was observed in the parent-offspring comparison among different subsites (left-sided and right-sided colon, rectum, and all CRC), the SIRs ranging from 1.74 to 1.84. When husbands were probands, the SIR in wives was 0.92 for colon cancer (left-sided 0.67 and right-sided 1.07), 0.98 for rectal cancer, and 0.96 for CRC. The risks for husbands when wives were probands were quite similar. None of the SIRs between spouses were significant, indicating lack of concordance between spouses that resided together for a minimum of 30 years. The risks between siblings were also increased particularly for cancer in the right-sided colon (SIR 6.89). The effect of shared childhood environmental effects were probed by analyzing the risks by age difference between the siblings. However, the risks were independent of the age difference. Data among spouses and siblings consistently point to the importance of heritable factors in familial CRC.

Age-specific familial risks for renal cell carcinoma with evidence on recessive heritable effects

BACKGROUND

Systematic comparisons of mode of inheritance for renal cell carcinoma (RCC) have not been carried out. The occurrence of cancer in parents and offspring may be due to dominant causes, whereas cancer affecting only siblings may indicate a recessive causation. Environmental effects need to be excluded.

METHODS

The Swedish Family-Cancer Database includes all Swedes born after 1931 with their biologic parents, totaling 10.2 million persons. Cancer data were retrieved from the Swedish Cancer Registry from years 1961 to 2000, included 2415 cases of RCC in offspring and 18531 in parents. Standardized incidence ratios (SIRs) and 95% CI limits were calculated for offspring whose parents or sibling were diagnosed with RCC.

RESULTS

The SIRs for siblings for RCC depended on their age difference. SIR was 7.63 (95% CI 3.63-14.08) when the age difference was less than 3 years and compared to 3.43 (95% CI 1.77-6.02) for large age difference. SIRs for familial risk of RCC were 1.73 (95% CI 1.31-2.26) when a parent and 4.58 (95% CI 2.87-6.94) when a sibling had RCC. Age-specific analysis of familial RCC among siblings revealed maxima at ages 40 to 49 and 60 to 68 years.

CONCLUSION

The findings in the present study offer evidence on recessive effects in early onset RCC.

Clinical epidemiology of testicular germ cell tumors

Clinical epidemiology is sometimes called the basic science of clinical medicine. In terms of the pathogenesis of testicular germ cell tumors (GCTs), clinical epidemiology analyzes suspected risk factors. The present review highlights the risk factors established so far and briefly summarizes those factors currently under investigation. In analogy to the methods of evidence based medicine, this review attributes levels of evidence to each of the putative risk factors. Level I represents highest quality of evidence while level V denotes the lowest level. So far, undescended testis (UDT), contralateral testicular GCT and familial testis cancer are established risk factors attaining high levels of evidence (levels I-III a). In a meta-analysis of 21 studies exploring the association of UDT with GCT risk, an over-all relative risk (RR) of 4.8 (95% confidence interval 4.0-5.7) was found. Contralateral testicular GCT involves a roughly 25-fold increased RR of GCT, while familial testis cancer constitutes a RR of 3-10. Infertility, testicular atrophy, and twin-ship represent risk factors with lesser levels of evidence (level III a). There is also some evidence for HIV infection being a predisposing factor for GCT (level IV a). Scrotal trauma is probably not associated with GCT risk. The estrogen excess theory implies high estrogen levels during the first trimester of pregnancy. As a consequence, primordial germ cells lose track of the normal developmental line and transform into premalignant cells that later become testicular intraepithelial neoplasia (TIN), the precursor of full-blown testicular GCT. Surrogate parameters for high gestational estrogen levels are investigated in case control studies. Such factors are maternal age >30 years, first-born, low birth weight, maternal breast cancer, high sex-ratio of siblings. So far, the sum of evidence is promising but still conflicting (especially for level III b). Another novel theory is the childhood nutrition hypothesis. This concept postulates a modulating or "catalyzing" effect by high dietary intake during childhood on the pathogenesis of testicular GCT. A surrogate parameter of early childhood nutrition is adult height. So far, 12 controlled studies have looked to the possible association of attained height and GCT risk of which six demonstrated a significant association. Thus, the sum of evidence corresponds to level III b. This concept is appealing because it would explain several hitherto unexplained epidemiological features of GCT.

Primary and secondary prevention in colorectal cancer

Colorectal cancer is an important public health problem: there are nearly one million cases of colorectal cancer diagnosed worldwide each year and half a million deaths. The geographic distribution of colorectal cancer follows the division between westernized versus developing countries, The highest rates are in North America, Australia and Europe. Rates in Africa and Asia are low, but are increasing in countries adopting western-style dietary habits. Given that the majority of cancers occur in older people, and with the ageing of the population in mind, this observation adds impetus to investigating prevention strategies to avoid some of this increase. High vegetable and fruit consumption has been associated with decreased risk of colorectal cancer in numerous observational studies, while high fibre intake seems to have a similar effect. Promising data have been obtained for aspirin and other non-steroidal anti-inflammatory drugs, and dietary calcium. A physically active lifestyle and maintenance of normal body weight are behavioural tools for prevention of colorectal cancer. Faecal occult blood testing has been shown to be effective in the prevention of about 20% of deaths from colorectal cancer, but few population-based screening programs have been initiated. Sigmoidoscopy and colonoscopy are potentially effective screening modalities; however, no randomized trial data have yet been reported. Overall, primary and secondary prevention, chemoprevention and screening research and implementation of these prevention strategies are priorities for reduction of colorectal cancer incidence and mortality.

Impact of Body Mass Index on Outcomes and Treatment-Related Toxicity in Patients With Stage II and III Rectal Cancer: Findings From Intergroup Trial 0114

Purpose

To study the relationship between body mass index (BMI) and rates of sphincter-preserving operations, overall survival, cancer recurrence, and treatment-related toxicities in patients with rectal cancer.

Patients and Methods

We evaluated a nested cohort of 1,688 patients with stage II and III rectal cancer participating in a randomized trial of postoperative fluorouracil-based chemotherapy and radiation therapy.

Results

Obese patients were more likely to undergo an abdominoperineal resection (APR) than normal-weight patients (odds ratio, 1.77; 95% CI, 1.27 to 2.46). When analyzed by sex, increasing adiposity in men was a strong predictor of having an APR (P < .0001). Obese men with rectal cancer were also more likely than normal-weight men to have a local recurrence (hazard ratio [HR], 1.61; 95% CI, 1.00 to 2.59). In contrast, obesity was not predictive of cancer recurrence in women, nor was BMI predictive of overall mortality in either men or women. Underweight patients had an increased risk of death (HR, 1.43; 95% CI, 1.08 to 1.89) compared with normal-weight patients but no increase in cancer recurrences. Among all study participants, obese patients had a significantly lower rate of grade 3 to 4 leukopenia, neutropenia, and stomatitis and a lower rate of any grade 3 or worse toxicity when compared with normal-weight individuals.

Conclusion

Increasing BMI in male patients with rectal cancer is associated with a decreased likelihood of sphincter preservation and a higher chance of local recurrence. For both men and women, overweight and obese patients experience less toxicity associated with adjuvant chemoradiotherapy, suggesting that actual body weight dosing of fluorouracil for obese patients is justified.

Prostate cancer screening, changing age-specific incidence trends and implications on familial risk

The incidence of prostate cancer has increased markedly during the past half century. We used the data from the Swedish Cancer Registry to follow the incidence trends and age-specific incidence up to 2002. Two different patterns in the age-incidence relationships were noted. The first one, prevailing until about 1995, was characterized by a preferential increase in incidence in men older than 70 years. In the second pattern, the increase extended preferentially to younger age groups, and it coincided with an introduction of opportunistic prostate specific antigen (PSA) screening, which was the probable cause of the large upward shift in the incidence between 1998 and 2000. The possible effects of diagnostic methods on familial risk estimates were tested by comparing age and calendar time differences among brothers who were diagnosed with prostate cancer, retrieved from the Swedish Family-Cancer Database. The 2 distributions were very different according to the Wilcoxon rank test (p < 0.0001). The data suggest that a diagnosis of prostate cancer in 1 brother leads to an early diagnosis in a second brother. The data are probably explained by the healthy brother seeking medical advice upon diagnosis in another brother. This effect is likely to bias familial risk estimates.

Obesity and colon cancer: Does leptin provide a link?

Obesity, a risk factor for colorectal cancer, is associated with elevated serum levels of leptin, the adipocyte-derived hormone, and insulin. Experimental and epidemiologic studies have indicated a role for insulin in the pathogenesis of colon cancer, and recent experimental studies have suggested a similar role for leptin. In a case-control study nested in the Janus Biobank, Norway, we measured serum levels of leptin and C-peptide (a marker of pancreatic insulin secretion) in cryopreserved prediagnostic sera from men (median age, 45 years) who were diagnosed with cancer of the colon (n = 235) or rectum (n = 143) after blood collection (median time, 17 years), and among 378 controls matched for age and date of blood collection. Conditional logistic regression analyses showed an approximately 3-fold increase in colon cancer risk with increasing concentrations of leptin up to an odds ratio (OR) of 2.72 (95% CI = 1.44-5.12) for top vs. bottom quartile (p(trend) = 0.008). The corresponding OR for C-peptide was 1.81 (95% CI = 0.67-4.86; p(trend) = 0.19). The risk estimates remained unchanged after mutual adjustment. No association of hormone levels with rectal cancer risk was found. Reproducibility of hormone measurements assessed by intraclass coefficients (ICCs) for paired samples taken 1 year apart was high for leptin (ICC = 0.82) but lower for C-peptide (ICC = 0.30). Our results suggest that leptin is a risk factor for colon cancer, and that leptin may provide a link between obesity and colon cancer. Leptin may be directly involved in colon tumorigenesis or it may serve as a sensitive and robust marker of an obesity-induced adverse endocrine environment. Only weak support for an association of insulin with colon cancer was found.

Height, body mass index, and prostate cancer: a follow-up of 950000 Norwegian men

The present study explored body mass index (BMI), height, and risk of prostate cancer in a large Norwegian cohort of 950000 men aged 20-74 years, whose height and weight were measured in a standardised way in the period 1963-1999. These were followed for an average of 21 years. The Cox proportional hazard models were used in the analyses. During follow-up, 33 300 histologically verified cases of prostate cancer were registered. The risk of prostate cancer increased by both BMI and height. The magnitude of the increase by BMI was modest, the relative risk (RR) of obese men (BMI>or=30) compared with normal weighted was 1.09 (95% CI: 1.04-1.15). However, the RR at age 50-59 years was 1.58 (95% CI: 1.29-1.94) in men being obese at about age 45 years compared with normal weighted men. The tallest men had an RR of 1.72 (95% CI: 1.46-2.04) compared with the shortest men. The overall effect of BMI on the incidence of prostate cancer was modest. The larger effect found in men aged 50-59 years might partly explain the previous inconsistent findings.

Obesity, tamoxifen use, and outcomes in women with estrogen receptor-positive early-stage breast cancer

BACKGROUND

Obesity is associated with both increased breast cancer risk and poorer prognosis after disease onset. However, little is known about the effect of obesity on treatment efficacy. We evaluated the association of obesity with outcomes and with tamoxifen efficacy in women with early-stage, hormone-responsive breast cancer participating in a multicenter cancer cooperative group clinical trial.

METHODS

The cohort consisted of 3385 women enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-14, a randomized, placebo-controlled trial evaluating tamoxifen for lymph node-negative, estrogen receptor (ER)-positive breast cancer. Hazards of breast cancer recurrence, contralateral breast tumors, other new primary cancers, and several mortality endpoints were evaluated in relation to body mass index (BMI), using statistical modeling to adjust for other prognostic factors. Median follow-up time was 166 months. All statistical tests were two-sided.

RESULTS

The hazard of breast cancer recurrence was the same among obese (BMI > or =30.0 kg/m2) women as compared with underweight and normal-weight women (BMI <25.0; hazard ratio [HR] = 0.98, 95% confidence interval [CI] = 0.80 to 1.18). Contralateral breast cancer hazard was higher in obese women than in underweight/normal-weight women (HR = 1.58, 95% CI = 1.10 to 2.25), as was the risk of other primary cancers (HR = 1.62, 95% CI = 1.16 to 2.24). Compared with normal-weight women, obese women had greater all-cause mortality (HR = 1.31, 95% CI = 1.12 to 1.54) and greater risk of deaths due to causes unrelated to breast cancer (HR = 1.49, 95% CI = 1.15 to 1.92). Breast cancer mortality was not statistically significantly increased for obese women (HR = 1.20, 95% CI = 0.97 to 1.49). Tamoxifen reduced breast cancer recurrence and mortality, regardless of BMI.

CONCLUSIONS

For women with lymph node-negative, ER-positive breast cancer, obesity was not associated with a material increase in recurrence risk or a change in tamoxifen efficacy. However, because obesity was associated with increased risks of contralateral breast cancer, of other primary cancers, and of overall mortality, it may influence long-term outcomes for breast cancer survivors.