Is restrained eating a risk factor for weight gain in a general population?

BACKGROUND: In modern societies characterized by abundant and accessible foods, restrained eating may become an adaptive behavior to limit weight gain. OBJECTIVE: We assessed the relations between eating behavior (EB) and adiposity in a general population over a 2-y period. DESIGN: We recruited 466 adults and 271 adolescents in 1999 on a geographical basis to participate in a longitudinal study. At the initial examination and 2 y later, they answered an EB questionnaire, the Three-Factor Eating Questionnaire-R18, which measured cognitive restraint (CR), uncontrolled eating, and emotional eating. On the same occasions, several measures of adiposity were also obtained: body mass index (BMI; in kg/m2), waist circumference, the sum of 4 skinfold thicknesses, and percentage body fat. Relations between EB and adiposity were tested separately in adults and adolescents by using mixed linear regressions after adjustment for age, sex, and (in adolescents) Tanner pubertal stage. RESULTS: At baseline, CR was positively associated with BMI in normal-weight subjects (mean BMI: 21.4 in the lowest to 23.3 in the highest CR quintile; P < 0.001) but not in overweight adults (P = 0.25). Initial CR did not predict change in adiposity variables (BMI change: P = 0.79 in adults, P = 0.57 in adolescents and young adults). Conversely, a high initial BMI was associated with a larger increase in CR (beta = 20.1, P < 0.0001 in adults; beta = 21.7, P = 0.003 in adolescents and young adults). CONCLUSIONS: Restrained eating is strongly associated with adiposity in normal-weight subjects but not in overweight subjects. However, restrained eating does not promote weight gain.     

Can I find a doctor? Availability of primary care physicians in the San Francisco Bay Area

OBJECTIVES: Primary care physicians function as "gatekeepers" in many managed care systems. With the rapid growth of managed care enrollment, it is crucial that patients have adequate access to primary care physicians. We investigated factors associated with new-patient appointment availability of primary care physicians in the San Francisco Bay Area. STUDY DESIGN: Observational cohort. POPULATION: Cross-sectional survey of primary care physician offices in 2 San Francisco Bay Area counties (n=438). OUTCOMES MEASURED: New-patient appointment availability. RESULTS: Seventy-five percent of primary care physicians participating in managed care had an appointment available for a new patient. Appointments were more likely to be available with primary care physicians who had been in practice for 10 years or less (odds ratio [OR]=4.2; 95% confidence interval [CI], 1.7-10.3), compared with more established physicians; and with primary care physicians who had graduated from a medical school outside of the United States (OR=3.5; 95% CI, 1.7-7.3), compared with US graduates. Appointments within 30 days were less available with female primary care physicians (OR=0.4; 95% CI, 0.2-0.7) than for male primary care physicians. CONCLUSIONS: The limited availability of appointments for new patients may create barriers to primary care in the San Francisco Bay Area, a region with high managed-care penetration.     

Is the duration of poverty and unemployment a risk factor for heavy drinking?

Research on the influence of socioeconomic status (SES) on heavy drinking of alcohol has provided contradictory findings. A limitation of the literature is that studies have primarily measured SES at one point in time. Inspired by the life course perspective and sociological research on chronic stress, this study uses data from the US National Longitudinal Survey of Youth (1979-1992 wave) to examine whether the duration of poverty and unemployment is a risk factor for heavy drinking. Results from logistic and ordinary least squares regression analyses demonstrate that longer durations of poverty and involuntary unemployment across a span of 13 years significantly predict being a heavy drinker and more frequent heavy drinking at ages 27-35 years. These effects are independent of gender, age, race/ethnicity, marital status, prior heavy drinking, and present SES. Overall, this study contributes to the literature that histories of poverty and involuntary unemployment have lasting effects on heavy drinking. More studies should use longitudinal data to explore the temporal dimension of SES.     

Is there a relationship between influenza vaccinations and risk of melanoma? A population-based case-control study

The aim of the present case-control study was to ascertain whether, in adults, yearly repeated anti-influenza vaccinations (AIV) enhance protection against cutaneous melanoma (CM), as do repeated febrile infections. Ninety-nine new cases of histologically confirmed CM and 104 healthy controls (matched to cases for sex, age, and skin colour) selected from the general population were examined in order to ascertain their skin type, the number of nevi on both arms, and the intensity of freckles on the face and the arms; in these subjects, a structured questionnaire was used to obtain information on age, sex, education, social class, exposure and susceptibility to sunlight, history of febrile infectious diseases, and vaccinations. The odds ratio (OR) and the 95% confidence interval (CI) were estimated by commonly used methods and by fitting models of logistic regression. The risk of CM was reduced in subjects with a history of febrile (temperature above 38.5 °C) infections in the 5 years prior to CM surgery (cases) or interview (controls), but was increased in those with voluntary exposure to sunlight in tropical countries. By holding the above factors constant at logistic regression analysis, it was found that a history of repeated AIV (3–5 times in the last 5 years) halved the risk (OR: 0.43; CI: 0.19–1.00; p < 0.05). With the variable `nevi on arms' included, the protective influence of repeated AIVs was observed in a similar magnitude. The inverse relationship found between melanoma and influenza vaccinations is unlikely to have depended on a bias, even if based on replies in a questionnaire, because neither the interviewers nor the interviewers were informed in advance of the working hypothesis.     

Is vitamin A consumption a risk factor for osteoporotic fracture?

Severe vitamin A toxicity is known to have adverse effects on skeletal health. Studies involving animal models and case reports have documented that hypervitaminosis A is associated with bone resorption, hypercalcaemia and bone abnormalities. More recently, some epidemiological studies have suggested that high habitual intake of vitamin A could contribute to low bone mineral content and fracture risk. The evidence relating to the possible deleterious role of vitamin A in bone health is of variable quality and is potentially confounded by collinearity of nutrient intake and difficulties in assessing vitamin A exposure. Furthermore, because intake of vitamin A varies between studies it is not possible to define an intake threshold associated with harm.     

Is 'clicky hip' a risk factor in developmental dysplasia of the hip?

BACKGROUND: The role of the 'clicky hip' symptom as a prognostic predictor of developmental dysplasia of hip (DDH) is controversial. We aim to study the role of isolated hip clicks as a prognostic predictor of DDH. MATERIAL AND METHODS: 235 babies with persisting or referred with clicky hip beyond six weeks of age were prospectively followed up to note the incidence of DDH. Of these 176 babies were referred for a hip click without additional risk factors. RESULTS: 7 out of 176 cases (4-IIa, 2-IIb, 1-IIc) had initial abnormal ultrasound examination based on Graf classification. However, all babies with isolated hip clicks eventually had normal hips on clinical and radiographic examination. DISCUSSION: While screening of babies with clicky hips does help in diagnosing the odd case of DDH this is not. consistently reproducible. Modifying the targeted ultrasound screening by including clicky hip as a risk factor will not reduce the incidence of missed cases. Isolated clicks in the hip joint beyond six weeks age are rarely a predictor of DDH. However when in doubt such cases should be referred to be reviewed by an orthopaedic surgeon or a radiologist experienced in hip ultrasound.     

Is zinc deficiency a risk factor for atherosclerosis?

The development of atherosclerosis is influenced by genetic, lifestyle and nutritional risk factors. Zn and metallothionein deficiency can enhance oxidative-stress-related signalling processes in endothelial cells, and since changes in available plasma Zn may affect the Zn status of the endothelium, Zn deficiency could be a risk factor for IHD. Although the association of Zn with many proteins is essential for their function, three key signalling processes are highlighted as being principal targets for the effect of Zn deficiency: the activation of NF-kappaB, the activation of caspase enzymes and the signalling of NO. The need to develop a reliable indicator of Zn status is critical to any epidemiological approach for studying the relationship between Zn status and disease incidence. Studies using appropriate animal models and investigating how the plasma Zn pool influences endothelial intracellular labile Zn would be helpful in appreciating the importance of Zn deficiency in atherogenesis.     

Does the risk of childhood diabetes mellitus require revision of the guideline values for nitrate in drinking water?

In recent years, several studies have addressed a possible relationship between nitrate exposure and childhood type 1 insulin-dependent diabetes mellitus. The present ecologic study describes a possible relation between the incidence of type 1 diabetes and nitrate levels in drinking water in The Netherlands, and evaluates whether the World Health Organization and the European Commission standard for nitrate in drinking water (50 mg/L) is adequate to prevent risk of this disease. During 1993-1995 in The Netherlands, 1,104 cases of type 1 diabetes were diagnosed in children 0-14 years of age. We were able to use 1,064 of these cases in a total of 2,829,020 children in this analysis. We classified mean nitrate levels in drinking water in 3,932 postal code areas in The Netherlands in 1991-1995 into two exposure categories. One category was based on equal numbers of children exposed to different nitrate levels (0.25-2.08, 2.10-6.42, and 6.44-41.19 mg/L nitrate); the other was based on cut-off values of 10 and 25 mg/L nitrate. We determined standardized incidence ratios (SIRs) for type 1 diabetes in subgroups of the 2,829,020 children with respect to both nitrate exposure categories, sex, and age and as compared in univariate analysis using the chi-square test for trend. We compared the incidence rate ratios (IRRs) by multivariate analysis in a Poisson regression model. We found an effect of increasing age of the children on incidence of type 1 diabetes, but we did not find an effect of sex or of nitrate concentration in drinking water using the two exposure categories. For nitrate levels > 25 mg/L, an increased SIR and an increased IRR of 1.46 were observed; however, this increase was not statistically significant, probably because of the small number of cases (15 of 1,064). We concluded that there is no convincing evidence that nitrate in drinking water at current exposure levels is a risk factor for childhood type 1 diabetes mellitus in The Netherlands, although a threshold value > 25 mg/L for the occurrence of this disease can not be excluded.     

Does calcium in drinking water modify the association between nitrate in drinking water and risk of death from colon cancer?

The objective of this study was to explore whether calcium (Ca) levels in drinking water modified the effects of nitrate on colon cancer risk. A matched case–control study was used to investigate the relationship between the risk of death from colon cancer and exposure to nitrate in drinking water in Taiwan. All colon cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth and year of death. Information on the levels of nitrate-nitrogen (NO₃-N) and Ca in drinking water have been collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's NO₃-N and Ca exposure via drinking water. We observed evidence of an interaction between drinking water NO₃-N and Ca intake via drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO₃-N exposure and risk of colon cancer mortality.     

Does ozonation of drinking water reduce the risk of bladder cancer?

BACKGROUND: Epidemiologic studies of drinking water disinfection byproducts have focused primarily on the carcinogenic potential of chlorination byproducts. Because drinking water has been ozonated in France for decades, we were able to assess the carcinogenic risk of the disinfection byproducts generated by both ozonation and chlorination. METHODS: We used data from a case-control study of bladder cancer conducted between 1985 and 1987 in 7 French hospitals. We compared 281 cases and 272 controls for whom we could reconstruct at least 70% of the residential exposure to drinking water contaminants over a 30-year period. RESULTS: When we took potential confounders and exposure to chlorination byproducts into account, the risk of bladder cancer decreased as duration of exposure to ozonated water increased (OR = 0.60 [95% CI = 0.3-1.3] for 1-9 years; OR = 0.31 [0.1-0.7] for 10 years or more). Simultaneously, the risk of bladder cancer increased with duration of exposure to chlorinated surface water and with the estimated trihalomethane content of the water. Our data suggest that ozonation reduces the risk associated with the chlorination of surface water and that ozonation alone could have an independent beneficial effect on bladder cancer risk. CONCLUSIONS: Our results are consistent with experimental evidence that ozonation in combination with chlorination decreases the concentration of trihalomethane in treated water and eliminates some of the mutagenicity of raw water.     

Is there still a problem with lead in drinking water in the European Union?

The presence of lead in drinking water poses a range of risks to human health, including the retardation of some aspects of child development, the inducement of abortion, and other clinical disorders. The extent of these risks has not been quantified at the European Union (EU) scale. A number of sampling methods are in use across the EU, some of which are inadequate for determining the concentrations of lead in drinking water at consumers' taps. In consequence, non-compliance with the EU standards for lead in drinking water has been under-estimated. Emerging data indicates significant non-compliance with these standards in some countries, particularly with the 10 mg l^-1 standard that will become a legal requirement in 2013; the current interim standard of 25 mg l^-1 is also exceeded in some locations. An initial estimate is that 25% of domestic dwellings in the EU have a lead pipe, either as a connection to the water main, or as part of the internal plumbing, or both, potentially putting 120 million people at risk from lead in drinking water within the EU. These issues are relevant to the implementation of the Protocol on Water and Health and to drinking water safety planning.     

Is radiographic vertebral fracture a risk factor for mortality?

Clinical fractures predict increased mortality risk, but few studies report mortality based on prevalent radiographically defined vertebral fracture. This study examined whether radiographically defined vertebral fracture is a risk factor for mortality in older adults. The 1,580 participants in California (631 men, 949 women) were aged > or =50 years in 1992-1996. Lateral spine radiographs, and information about medical history and behaviors, were obtained. Overall, 55 (8.7%) men and 123 (13%) women had at least one prevalent fracture at baseline; of these, 48 women and 14 men had two or more. Over 7.6 years, 460 participants died, 27.6% without and 41.0% with prevalent fractures (p < 0.001). Prevalent vertebral fracture was not associated with all-cause mortality in both sexes combined (adjusted hazard ratio = 1.09, 95% confidence interval: 0.84, 1.42) or sex-specific analyses (women: adjusted hazard ratio = 1.15, 95% confidence interval: 0.83, 1.59; men: adjusted hazard ratio = 0.89, 95% confidence interval: 0.55, 1.46). However, women with two or more prevalent fractures had increased risk of all-cause mortality (adjusted hazard ratio = 1.56, 95% confidence interval: 1.01, 2.40; p = 0.04). Women with any prevalent vertebral fractures also had increased mortality risk from "other" causes (adjusted hazard ratio = 1.59, 95% confidence interval: 1.03, 2.45; p = 0.04) but not cardiovascular disease or cancer. A single radiographic vertebral fracture is not a risk for mortality in older women; larger, longer studies of men and those with two or more radiographic vertebral fractures are needed.     

Is diabetes mellitus a risk factor for HCV infection?

The aim of this study was to investigate whether or not the diabetes mellitus may be considered a risk factor for the HCV infection. The HCV seroprevalence was evaluated in 254 diabetic subjects, whose anamnestic data and risk factors are known, in comparison to 223 first-time blood donors, carefully age- and gender-matched. The statistical analysis showed that the studied groups belonged to the same population (Mann-Whitney U test) and that there were no significant differences between cases and controls as regards HCV prevalence (Yates corrected chi 2 test). The obtained data underline the importance of the control group selection, especially in the studies considering age-related pathologies. The authors disprove type 2 diabetes as a risk factor for the HCV infection and consider that this is a valid hypothesis only when the hepatitis C was unknown and not adequate prevention was used.     

Is calcium supplementation a risk factor for cardiovascular diseases in older women?

Low intake of dietary calcium is related to bone loss and fragility fracture in older adults, especially postmenopausal women. Contradictory findings have been reported from studies that investigated the association between calcium supplementation and hypertension and the risk of stroke and cardiovascular disease. Misinterpretation of findings from studies that are not primarily designed to address these issues might overshadow the benefits of dietary calcium. Until well-designed studies address the current uncertainties, the possible detrimental effect (e.g., hypercalcemia and its complications) of higher-than-recommended calcium intake should be balanced against the likely benefits of calcium on bone, particularly in elderly women.     

Is country of birth a risk factor for acute hospitalization for cardiovascular disease in Victoria, Australia?

International mortality studies show that some subgroups of migrants have a higher risk of Cardiovascular Disease (CVD) than the native-born. To investigate whether country of birth increases the risk for acute myocardial infarction (AMI) and cerebral infarction (stroke) hospitalization in Victoria, Australia. A retrospective analysis of Victorian AMI (ICD-10-AM codes I21 and I22) and stroke (ICD-10-AM I63 and I64) discharges from routinely collected hospital data in 2001-2002 was conducted. The outcome measures were directly age standardized rate ratios (RRs) of AMI and stroke hospitalization, calculated using 2001 Australian census data, with the Australian-born as the reference group. Males from 4 ethnic groups--USSR/Baltic; Southern Asia; Middle East; and Eastern Europe, displayed higher risk for AMI hospitalization than Australian-born men, whereas males and females from Southeast Asia and Northeast Asia were at lower risk. Furthermore, males from Western Europe and females from the Pacific were also at lower risk. Females from the Middle East, Southern Asia, and Southern Europe were at higher risk of stroke hospitalization than Australian-born women; in contrast, males from Eastern Europe, NorthAsia, Southern Asia, Southern Europe, and the United Kingdom and Ireland were at lower risk. Risk for AMI and stroke hospitalization varies by country of birth in comparison with the Australian-born population. It will be import to identify the factors associated with these varying risks in order to target preventive strategies aimed at reducing risk of AMI and stroke.