Comparison of micronutrient intake measured by a dietary questionnaire and biochemical indicators of micronutrient status.

We compared the intake of 12 micronutrients as reported on a semiquantitative food frequency questionnaire with corresponding biochemical indicators of nutrient status in a sample of 57 males and 82 females aged 40-83 y. Age-, sex-and energy-adjusted correlation coefficients ranged from near zero for thiamin, vitamin A, and zinc to 0.63 for folate. Correlation coefficients between intake and the biochemical measures were > 0.30 for carotenoids, vitamin D, vitamin E, vitamin B-12, folate, and vitamin C. Differences of 50% or more were observed between extreme quartiles of intake for mean plasma concentrations of folate, vitamin B-12, and vitamin C. Excluding nutrient supplement users generally reduced the correlations. These data demonstrate that food frequency questionnaires can provide valid information on intake for a number of micronutrients.

Effect of vitamin C supplementation on lipoprotein cholesterol, apolipoprotein, and triglyceride concentrations.

Plasma ascorbic acid (AA) frequently is positively correlated with high-density-lipoprotein (HDL) cholesterol and inversely related to total cholesterol concentration. To determine if vitamin C intake can alter cholesterol concentration, we examined the effect of vitamin C supplementation (1 g/d) on lipoprotein cholesterol and triglyceride levels in 138 subjects, aged 20 to 65 years, who completed an 8-month randomized, double-blinded, placebo-controlled trial. Individuals with higher levels of plasma AA (> 80 mumol/L for men and > 90 mumol/L for women), HDL cholesterol (> 1.4 mmol/L for men and > 1.7 mmol/L for women), and total cholesterol (> 6.7 mmol/L) were excluded from this trial. We observed no overall effect of supplementation on plasma concentrations of HDL, LDL, or total cholesterol, apolipoprotein (apo) B, or triglyceride. We did observe a marginally significant (P < 0.10) increase of 1.9 mumol/L (5.3 mg/dL) in apo A-I concentration with supplementation and a significant (P < 0.05) difference of 0.10 mmol/L (3.8 mg/dL) in HDL cholesterol concentration between vitamin C and placebo treatment in a nonrandomized subgroup of individuals (n = 43) and a baseline plasma AA level less than 55 mumol/L. Although the apo A-I concentration increase was only marginally significant with supplementation, change in plasma AA concentration was significantly (P < 0.05) correlated with change in apo A-I concentration in the entire sample. The overall results of this trial were negative, but our data do not allow us to rule out the possibility that vitamin C supplementation might increase HDL cholesterol or apo A-I concentrations among individuals with lower plasma AA levels.

Case-control study of discharge from the U.S. Army for disabling occupational knee injury: the role of gender, race/ethnicity, and age.

BACKGROUND: Occupational injuries are responsible for more lost time from work, productivity, and working years of life than any other health condition in either civilian or noncombat military sectors. Injuries, not illnesses, are the leading cause of morbidity and mortality among U.S. Army personnel. We examined the separate and joint roles of gender, race/ethnicity, and age in the odds of discharge from the Army for disabling knee injury. METHODS: A total of 860 women and 7868 men were discharged from the Army between 1980 and 1995 for knee-related disability and met all inclusion criteria for this study. All women and a subsample of 1005 men were included in these analyses, along with a simple random sample of three controls per case, stratified by gender, drawn from the population of all active-duty enlisted soldiers in each year from 1980 to 1995. We identified predictors of the occurrence or nonoccurrence of discharge from the Army for disabling knee injury using unconditional multiple logistic regression analyses. RESULTS: We found relations between the risk of knee-related disability and age and race, with marked effect modification by gender. Non-Caucasian men and women were at lower risk than Caucasians at all ages. At most ages, Caucasian women were at higher risk than Caucasian men, and non-Caucasian women were at lower risk than non-Caucasian men. Within race/ethnicity and gender, the risks for men showed an inverted "U" shape with increasing age, and the risks for women showed a "J" shape with increasing age. CONCLUSIONS: Age, race/ethnicity, and gender interactions are important in occupational injury. Differences in risk may be related to differences in work assignments, leisure activities, physical or physiological differences, or the ways in which disability compensation is granted.

Manufacturing characteristics associated with strut fracture in Björk-Shiley 60 degrees Convexo-Concave heart valves.

Björk-Shiley Convexo-Concave (CC) valves sometimes experience fracture of the outlet strut. Previously implicated valve characteristics that predict strut fracture include larger valve size, larger opening angle (70 degrees vs 60 degrees), remilling, weld date, and implant in the mitral position. While the associations between risk, size, and opening angle suggest that part of the elevated incidence of strut fracture might be due to the design of the Björk-Shiley valves, only a small fraction of implanted valves have experienced strut fracture. In consequence, previously unexamined variations in the manufacturing process have been suggested as possible factors affecting the failure risk of individual valves; materials, manufacturing steps, quality control, and specific workers have all been put forward as potential explanations for valve-to-valve variation in risk. We conducted a case-control study of CC60 degrees valves implanted in the USA and Canada and manufactured between January 1, 1979 and March 31, 1984. Cases included all verified strut fractures reported to the manufacturer from 1979 through January, 1992. up to 10 controls were selected for each case. Controls were matched to cases on implanting surgeon and were required to have been implanted and functioning at least as long as their respective case valves. We reviewed case and control manufacturing records. There were 150 cases and 1095 surgeon-matched controls. Large mitral valves were at greatest risk of strut fracture; 33mm mitral valves were estimated to be 23 times more likely to fracture than 21-25mm aortic valves. Valves welded in 1979 and 1980 were less likely to fracture than those welded in any other time period; however, no specific manufacturing procedures or personnel were uniquely associated with this time period. Valves with more flexible outlet struts, as determined by the hook deflection and load deflection tests during manufacture, appear to have been at higher risk than valves with more rigid outlet struts. There were three welders who had worked on a sufficient number of valves to allow separate estimation of the risk in the valves they welded. One welder's work was associated with about one-third the risk of valves worked on by the other two. Examination of receiver operating characteristic curves revealed, however, that welder identity added little to the discriminating information already available in the form of valve size and implant position. It is concluded that welder identity and strut flexibility appear to contribute to the risk of outlet strut fracture in Björk-Shiley CC60 degrees valves. Neither of these factors, however, is sufficient to account for much of the previously unexplained variation in risk. No other characteristic measurable in existing manufacturing records appears to predict risk of strut fracture in any useful way.

Deep venous thrombosis associated with corporate air travel.

BACKGROUND: Deep venous thrombosis (DVT) is commonly seen among bedridden and postoperative patients. Its association with travel may also make DVT an occupational health risk to otherwise healthy business travelers. We estimated the incidence of and risk factors for DVT among 8,189 World Bank employees and a subset of 4,951 international business travelers. METHODS: Occurrence of DVT between 1995 and 1998 was determined using 1) medical insurance claims; 2) Workers' Compensation claims; and 3) intra-office E-mail solicitation followed by interview. For each insurance claim case, 10 controls were randomly selected from among World Bank employees insured during the same month and year as the case's claim was filed, and case-control analyses were performed to identify potential predictors or risk factors for DVT. RESULTS: Thirty individuals filed claims for DVT of the legs (annual incidence rate: 0.9 per 1,000 employees); three of these claims were filed within 30 days after a travel mission. Two employees reported DVT as a Workers' Compensation injury, and five staff with verified DVT participated in interviews. After controlling for age and gender, no association with any travel-related covariate was seen. Results of analyses considering all thrombophlebitis and thromboembolism followed the same pattern. The average annual incidence of DVT occurring within 30 days of mission among traveling staff ranged from 0.10 per 1,000 to 0.25 per 1,000 travelers, depending on the case-finding method. CONCLUSION: No association between DVT and travel was observed after adjustment for gender and age. These results, however, are preliminary, and due to the rarity of DVT, based on small numbers.

Relationship in humans between ascorbic acid consumption and levels of total and reduced ascorbic acid in lens, aqueous humor, and plasma.

The relationships between plasma, aqueous humor and lens ascorbic acid levels are examined in 131 samples from 127 patients. Mean ascorbate intake for nonsupplemented individuals was 148 mg/day or over two times the recommended daily allowance. A subset of 44 patients participated in a trial to assess the impact of vitamin C supplementation of 2 grams per day on aqueous and lens ascorbic acid levels. Such supplementation significantly increased both total and reduced ascorbic acid levels in plasma and aqueous and total ascorbic acid in the lens. Correlation coefficients relating total and reduced ascorbic acid levels in the three tissues ranged from 0.42 to 0.19 (p less than 0.05 for all correlation coefficients). Over 60% of the ascorbate was present in the reduced form in plasma and aqueous, and about 50% of the lens ascorbate was in the reduced form.

Effectiveness of an outside-the-boot ankle brace in reducing parachuting related ankle injuries.

OBJECTIVES: To examine the efficacy of an outside-the-boot parachute ankle brace (PAB) in reducing risk of ankle injury to army paratrooper trainees and to identify inadvertent risks associated with PAB use. DESIGN: The authors compared hospitalization rates for ankle, musculoskeletal, and other traumatic injury among 223,172 soldiers trained 1985-2002 in time periods defined by presence/absence of PAB use protocols. Multiple logistic regression analysis estimated adjusted odds ratios (OR) and 95% confidence intervals for injury outcomes, comparing pre and post brace periods to the brace protocol period. SETTING: A research database consisting of training rosters from the US Army Airborne training facility (Fort Benning, GA) occupational, demographic, and hospitalization information. MAIN OUTCOME MEASURES: Injuries were considered training related if they occurred during a five week period starting with first scheduled static line parachute jump and a parachuting cause of injury code appeared in the hospital record. RESULTS: Of 939 parachuting related hospitalizations during the defined risk period, 597 (63.6%) included an ankle injury diagnosis, 198 (21.1%) listed a musculoskeletal (non-ankle) injury, and 69 (7.3%) cited injuries to multiple body parts. Risk of ankle injury hospitalization was higher during both pre-brace (adjusted OR 2.38, 95% CI 1.92 to 2.95) and post-brace (adjusted OR 1.72, 95% CI 1.27 to 2.32) periods compared with the brace protocol period. Odds of musculoskeletal (non-ankle) injury or injury to multiple body parts did not change between the brace and post-brace periods. CONCLUSION: Use of a PAB during airborne training appears to reduce risk of ankle injury without increasing risk of other types of traumatic injury.

Ascorbic acid and plasma lipids.

We examined the association between plasma lipids and total ascorbic acid in 256 men and 221 women age 20-65 years. Among men, we observed that high-density lipoprotein (HDL) cholesterol was 2.1 mg per dl higher, total:HDL cholesterol was 5.4% lower, total cholesterol was 4.8 mg per dl lower, low-density lipoprotein (LDL) cholesterol was 5.6 mg per dl lower, and triglyceride was 5.2% lower for each 0.5 mg per dl increment in ascorbic acid. The association between ascorbic acid and total:HDL cholesterol ratio in men was modified by glucose concentration. Among women, we observed that HDL cholesterol was 14.9 mg per dl higher for women with ascorbic acid levels < or = 1.05 mg per dl and 0.9 mg per dl lower for women with ascorbic acid levels > 1.05 mg per dl for each 0.5 mg per dl increment in ascorbic acid. Total:HDL cholesterol ratio was 10.9% lower for women with ascorbic acid concentrations < or = 1.45 mg per dl and 0.6% higher for women with ascorbic acid concentrations > 1.45 mg per dl for each 0.5 mg per dl increment. The associations among ascorbic acid concentration, total and LDL cholesterol, and triglyceride concentrations were weak or absent among women. These results are consistent with earlier observations relating ascorbic acid and HDL cholesterol and indicate that ascorbic acid might also be related to total and LDL cholesterol concentrations in men.

Patient factors associated with strut fracture in Björk-Shiley 60 degrees convexo-concave heart valves.

BACKGROUND: Previously established predictors of outlet strut fracture in Björk-Shiley convexo-concave (CC) valves include larger valve size, larger opening angle (70 degrees versus 60 degrees), younger age at implant, and date of manufacture. We sought to identify patient characteristics that might be predictive of strut fracture and to refine the estimates associated with previously identified predictors. METHODS AND RESULTS: We conducted a case-control study of CC60 degrees valves implanted in the United States and Canada and manufactured between January 1, 1979, and March 31, 1984. Cases included all valves with verified outlet strut fractures reported to the manufacturer from January 1979 through January 1992. Up to 10 controls were selected for each case. Control valves were matched according to implanting surgeon and were required to have been functioning at least as long as their matched case valves. Case and control medical records were reviewed for information on patient medical history before the valve implant. There were 96 case and 634 control valves for which clinical data were available. Patient age and valve size and implant position were confirmed as important determinants of fracture. There was a strong inverse gradient of risk with age. The risk of fracture was 42% lower for each 10-year increment of patient age at time of implant. Large mitral valves were at greatest risk of strut fracture, with the largest mitral valves (33 mm) estimated to be 33 times more likely to fracture than the smallest (21 to 25 mm) aortic valves. Date of manufacture was also associated with risk; valves welded from mid-1981 through March 1984 were more likely to fracture than those manufactured in 1979 and 1980. Body surface area < 1.5 m2 was associated with 1/16 the risk of body surface area > or = 2.0 m2. No other patient factor was strongly associated with the risk of strut fracture. CONCLUSIONS: Few patient features identifiable in the implant record are predictive of strut fracture. Our analysis supports previous work in identifying valve size, patient age, and date of manufacture as predictors of fracture and adds body surface area. A number of these associations suggest that conditions associated with higher cardiac output may also place patients at increased risk.

Critical review of the epidemiological literature on the potential cardiovascular effects of occupational carbon disulfide exposure.

OBJECTIVES: Occupational carbon disulfide (CS(2)) exposure has been associated with a variety of health effects since its introduction in the mid-19th century. Much of the epidemiological interest, especially since the 1960s, has focused on associations with cardiac effects. However, considerable differences in study approach, disease outcome, CS(2) exposure level, and control of confounding factors have produced mixed results and conclusions. This critical review presents a synthesis of the most relevant and best quality studies to better understand these associations. METHODS: Using specific criteria to assess methodological and scientific quality, we identified 37 studies with the potential to inform on at least one of the following questions: (1) Has a relationship between CS(2) exposure and coronary heart disease (CHD) mortality been reasonably demonstrated? If so, at what apparent exposure levels has it been observed? (2) Among studies of workers routinely exposed to CS(2) at levels greater than 20 ppm, have any health effects or indicators of CHD been observed consistently? (3) Among occupational groups exposed to CS(2) at levels less than 20 ppm, have any health effects or indicators of CHD been observed consistently? RESULTS: Several CHD-related effects have been examined relative to various levels of occupational CS(2) exposure. Overall, there was remarkably little consistency of CHD effects observed, including CHD mortality. CONCLUSIONS: Although a physiological effect of CS(2) exposure on CHD is plausible, the epidemiological evidence for an association between CS(2) exposure and various cardiac risk indicators is mixed. The only somewhat consistent finding, of CS(2) exposure on total and/or LDL cholesterol level, may be due to residual confounding by other time-dependent risk factors. If real, however, it appears to be of small magnitude and uncertain clinical importance.

Risk factors for occupational knee related disability among enlisted women in the US Army.

AIMS: To identify sociodemographic and occupational determinants of knee related disability discharge from the US Army among enlisted women, and to investigate effect modification. METHODS: A case-control study of 692 cases of knee related disability discharge and 2080 incidence density matched controls nested within the population of all 244 000 enlisted women on active duty in the US Army, 1980-97. We used logistic regression to identify determinants of disability, stratified to explore effect modification by demographic and work characteristics. RESULTS: The risk of disability discharge was twice as high (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.71 to 3.47) for the oldest (33-60 years) versus the youngest (17-21 years) women. Non-whites had lower risk than whites (OR 0.5, 95% CI: 0.41 to 0.60), as did married (OR 0.7, 95% CI: 0.54 to 0.81) relative to non-married women. Those of lower rank (pay grades E1-E3) were at five times the risk of disability discharge compared to those of higher ranks (pay grades E4-E9, OR 5.0, 95% CI: 2.86 to 8.33), while ORs were highest for those with longer duration of service compared to women on active duty for a year or less (OR 1.4, 95% CI: 0.8 to 2.55 after 12 years). Race modified several effects, including that of rank. Age, duration of service, and pay grade were too highly correlated to draw firm conclusions about their independent modifying effects on risk of disability discharge from the Army. CONCLUSIONS: Sociodemographic factors had larger effects than occupational characteristics on risk of knee related disability discharge from the US Army. Interactions suggest subgroups at differing risk levels that might be targeted for more detailed investigations.

Cancer control knowledge, attitudes, and perceived skills among medical students.

BACKGROUND: The Cancer Prevention and Control Education (CPACE) program aims to strengthen and coordinate curriculum offerings in cancer prevention and control for medical, graduate nursing and public health students. METHODS: Students were surveyed on cancer-related knowledge and confidence as part of needs assessment and evaluation efforts. The students completed self-administered surveys (response rate 78%). Descriptive and stratified analysis and ANOVA were conducted. RESULTS: Knowledge and confidence generally increased with each successive class year, but confidence varied markedly across specific counseling scenarios and by gender. While the students overall reported greater confidence in performing an examination than in interpreting the results, confidence varied significantly across specific types of examinations. CONCLUSIONS: Understanding of basic information about common cancers was disappointing. Confidence to perform and interpret examinations could be higher, especially for opposite-gender screening examinations. Implications of the findings for CPACE curriculum development are discussed.

Mental health insurance claims among spouses of frequent business travellers.

OBJECTIVES: Following up on two earlier publications showing increased psychological stress and psychosocial effects of travel on the business travellers this study investigated the health of spouses of business travellers. METHODS: Medical claims of spouses of Washington DC World Bank staff participating in the medical insurance programme in 1997-8 were reviewed. Only the first of each diagnosis with the ninth revision of the international classification of diseases (ICD-9) recorded for each person was included in this analysis. The claims were grouped into 28 diagnostic categories and subcategories. RESULTS: There were almost twice as many women as men among the 4630 identified spouses. Overall, male and female spouses of travellers filed claims for medical treatment at about a 16% higher rate than spouses of non-travellers. As hypothesised, a higher rate for psychological treatment was found in the spouses of international business travellers compared with non-travellers (men standardised rate ratios (RR)=1.55; women RR=1.37). For stress related psychological disorders the rates tripled for both female and male spouses of frequent travellers (>or= four missions/year) compared with those of non-travelling employees. An increased rate of claims among spouses of travellers versus non-travellers was also found for treatment for certain other diagnostic groups. Of these, diseases of the skin (men RR=2.93; women RR=1.41) and intestinal diseases (men RR=1.31; women RR=1.47) may have some association with the spouses' travel, whereas others, such as malignant neoplasms (men RR=1.97; women RR=0.79) are less likely to have such a relation. CONCLUSION: The previously identified pattern of increased psychological disorders among business travellers is mirrored among their spouses. This finding underscores the permeable boundary between family relations and working life which earlier studies suggested, and it emphasises the need for concern within institutions and strategies for prevention.

Descriptors of alcohol consumption among noninstitutionalized nonalcoholic elderly.

This paper describes relationships between reported alcohol consumption and selected sociodemographic and health variables. Two hundred and four men and 367 women aged 60-95 years were examined as part of a nutritional status survey of elderly. Fifty-three percent of men and 44% of women reported drinking at least 2 g of alcohol per week. Men were more likely to drink than women, and the level of alcohol consumption decreased with age. Drinking was positively associated with education (p less than 0.01) and negatively associated with recent medical care (p less than 0.01), history of MI (p less than 0.05), and denture use (p less than 0.05). Among drinkers, reported alcohol intake was higher for subjects less than age 70 (p less than 0.01), males (p less than 0.01), the college educated (p less than 0.01), and smokers (p less than 0.05). Level of alcohol intake was lower for those who had received medical care in the year preceding study participation (p less than 0.05). Identical results were observed for alcohol intake expressed as percent of total calories. Intake ranged from 3.8% of total calories among subjects 80+ years old to 6.2% of total calories among 60-69-year-olds.