Abstract P6-10-02: Not presented

This abstract was not presented at the conference.

Citation Format: McDonnell SL, Baggerly CA, French CB, Baggerly LL, Garland CF, Gorham ED, Lappe JM. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-10-02.

Incidence rate of type 2 diabetes is >50% lower in GrassrootsHealth cohort with median serum 25-hydroxyvitamin D of 41 ng/ml than in NHANES cohort with median of 22 ng/ml

Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with lower risk of type 2 diabetes. This study compared incidence rates of type 2 diabetes among participants aged ≥20 years in two U.S. cohorts with markedly different median 25(OH)D concentrations. The median 25(OH)D concentration in the GrassrootsHealth (GRH) cohort was 41 ng/ml (N=4933) while in the 2005-6 National Health and Nutrition Examination Survey (NHANES) it was 22 ng/ml (N=4078) (P<0.0001). The adjusted annual incidence rate of type 2 diabetes was 3.7 per 1000 population (95% confidence interval=1.9, 6.6) in the GRH cohort, compared to 9.3 per 1000 population (95% confidence interval=6.7, 12.6) in NHANES. In the NHANES cohort, the lowest 25(OH)D tertiles (<17, 17-24 ng/ml) had higher odds of developing diabetes than the highest tertile (OR: 4.9, P=0.02 and 4.8, P=0.01 respectively), adjusting for covariates. Differences in demographics and methods may have limited comparability. Raising serum 25(OH)D may be a useful tool for reducing risk of diabetes in the population.

Lower prediagnostic serum 25-hydroxyvitamin D concentration is associated with higher risk of insulin-requiring diabetes: a nested case-control study

AIMS/HYPOTHESIS

Low serum 25-hydroxyvitamin D [25(OH)D] concentration may increase risk of insulin-requiring diabetes.

METHODS

A nested case-control study was performed using serum collected during 2002-2008 from military service members. One thousand subjects subsequently developed insulin-requiring diabetes. A healthy control was individually matched to each case on blood-draw date (±2 days), age (±3 months), length of service (±30 days) and sex. The median elapsed time between serum collection and first diagnosis of diabetes was 1 year (range 1 month to 10 years). Statistical analysis used matched pairs and conditional logistic regression.

RESULTS

ORs for insulin-requiring diabetes by quintile of serum 25(OH)D, from lowest to highest, were 3.5 (95% CI 2.0, 6.0), 2.5 (1.5, 4.2), 0.8 (0.4, 1.4), 1.1 (0.6, 2.8) and 1.0 (reference) (p (trend) <0.001). The quintiles (based on fifths using serum 25(OH)D concentration in the controls) of serum 25(OH)D in nmol/l, were <43 (median 28), 43-59 (median 52), 60-77 (median 70), 78-99 (median 88) and ≥100 (median 128).

CONCLUSIONS/INTERPRETATION

Individuals with lower serum 25(OH)D concentrations had higher risk of insulin-requiring diabetes than those with higher concentrations. A 3.5-fold lower risk was associated with a serum 25(OH)D concentration ≥60 nmol/l.

P1-08-08: Higher Prediagnostic Serum 25-Hydroxyvitamin Is Associated with Substantially Lower Incidence of Breast Cancer: Prospective Study

Background: Recent studies have found lower risk of breast cancer in women with higher serum concentrations of 25-hydroxyvitamin D (25[OH]D), with few exceptions. To help resolve remaining differences, a nested case-control study was conducted. Material and Methods: Serum was provided by the Department of Defense Serum Repository for 600 new cases of breast cancer and 600 controls individually matched on age ±6 months; date blood was drawn ±2 days; and active-duty status; and were analyzed for 25(OH) D by a chemiluminescent assay. Mean age was 40 years (SD ±7 years, range 20–56 years). The individuals were 55% white, 33% African-American, and 11% other races. Mean serum 25(OH)D concentrations by quintile, from lowest to highest, were 11, 18, 24, 30 and 42 ng/ml. Dividing points were &lt;15, 15–21, 22–27, 28–35, and &gt;35 ng/ml. Results: Race-adjusted odds ratios for breast cancer, from lowest to highest quintile of serum 25(OH)D, were 1.0 (reference), 0.58, 0.78, and 0.52 (ptrend &lt; 0.05). The difference between risk of breast cancer in the lowest and highest 25(OH)D quintiles was significant (p &lt; 0.05). The association of low serum 25(OH)D with high risk of breast cancer was strongest for serum drawn during the 3 month period preceding diagnosis of breast cancer, and in white women. There was a strong linear inverse relationship between serum 25(OH) D and risk of breast cancer in this group. A similar trend was present for overall data including all intervals and races, but was weaker and not as clearly linear.

Discussion: Consistent with most previous research, women whose serum 25(OH)D concentration was high (42 ng/ml) had approximately half the risk of breast cancer as those whose serum 25(OH)D was low (11 ng/ml). The trend was similar after adjustment for race. The favorable association of serum 25(OH)D with risk of breast cancer apparently was strongest during the final few doublings of the tumor mass preceding diagnosis in this population. (An alternative, far less likely, interpretation, is that the tumor mass might adversely influence 25(OH)D concentration). A serum 25(OH)D concentration of 42 ng/ml can be achieved with vitamin D3 intake of 4000 IU/day. This is the safe daily upper level intake of the National Academy of Sciences-Institute of Medicine (NAS-IOM December 2010 monograph). While further research would be beneficial, such intake should be recommended as a useful tool for prevention of breast cancer. Serum 25(OH)D should be monitored on a routine basis, when feasible, to ensure that at least 40 ng/ml is maintained throughout the year, and 150 ng/ml is not exceeded. This hygienic measure could prevent approximately 50% of breast cancer in the US. (The views expressed in this abstract are those of the authors and do not represent positions of the Department of the Navy, Department of the Army, the Department of Defense or the US Government.)

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-08.

Incidence of insulin-requiring diabetes in the US military

AIMS/HYPOTHESIS

The aim of the study was to determine age- and race-related, and overall incidence rates of insulin-requiring diabetes in adults in the US military.

METHODS

Electronic records for admissions to US military and Tricare hospitals during 1990-2005 and visits to military clinics during 2000-2005 were identified using the Career History Archival Medical and Personnel System at the Naval Health Research Center, San Diego, CA, USA. Population data were obtained from the Defense Manpower Data Center and Defense Medical Epidemiology Database.

RESULTS

In men there were 2,918 new cases of insulin-requiring diabetes in 20,427,038 person-years at ages 18-44 years (median age 28 years) for a total age-adjusted incidence rate of 17.5 per 100,000 person-years (95% CI 16.4-18.6). Incidence rates were twice as high in black men as in white men (31.5 vs 14.5 per 100,000, p < 0.001). In women there were 414 new cases in 3,285,000 person-years at ages 18-44 years (median age 27 years), for a total age-adjusted incidence rate of 13.6 per 100,000 (95% CI 12.4-14.9). Incidence rates were twice as high in black women as in white women (21.8 vs 9.7 per 100,000, p < 0.001). In a regression model, incidence of insulin-requiring diabetes peaked annually in the winter-spring season (OR 1.46, p < 0.01). Race and seasonal differences persisted in the multivariate analysis.

CONCLUSIONS/INTERPRETATION

Differences in incidence rates by race and season suggest a need for further research into possible reasons, including the possibility of a contribution from vitamin D deficiency. Cohort studies using prediagnostic serum 25-hydroxyvitamin D should be conducted to further evaluate this relationship.

The association between ultraviolet B irradiance, vitamin D status and incidence rates of type 1 diabetes in 51 regions worldwide

AIMS/HYPOTHESIS

This study is an analysis of the relationship between ultraviolet B (UVB) irradiance, the primary source of circulating vitamin D in humans, and age-standardised incidence rates of type 1 diabetes mellitus in children, according to region of the world.

METHODS

The association of UVB irradiance adjusted for cloud cover to incidence rates of type 1 diabetes in children aged <14 years during 1990--1994 in 51 regions worldwide was assessed using multiple regression. Incidence data were obtained from the Diabetes Mondial Project Group.

RESULTS

Incidence rates were generally higher at higher latitudes (R2 = 0.25, p < 0.001). According to multiple regression, UVB irradiance adjusted for cloud cover was inversely associated with incidence rates (p < 0.05), while per capita health expenditure (p < 0.004) was positively associated (overall R2 = 0.42, p < 0.0001).

CONCLUSIONS/INTERPRETATION

An association was found between low UVB irradiance and high incidence rates of type 1 childhood diabetes after controlling for per capita health expenditure. Incidence rates of type 1 diabetes approached zero in regions worldwide with high UVB irradiance, adding new support to the concept of a role of vitamin D in reducing the risk of the disease.

Serum 25-hydroxyvitamin D, parathyroid hormone, and bone mineral density in men: the Rancho Bernardo study

INTRODUCTION

This study examined the distribution and determinants of serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) and their associations with bone mineral density (BMD) at the hip and spine in 414 older men (mean age 74 years) living in southern California.

METHODS

At a clinic visit (1997-2000), demographic and lifestyle information, fracture history, and medication use were recorded; venous blood for serum 25OHD and PTH was obtained; and BMD was measured at the hip and spine.

RESULTS

Only one man had vitamin D deficiency (25OHD <20 nmol/l), but 15.5% of the men had high parathyroid levels (PTH >or=65 pg/ml). The mean 25OHD and PTH levels were 109.0 nmol/l and 50.3 pg/ml, respectively. Overall, 21.5% used calcium and 9.7% used vitamin D supplements. Serum 25OHD decreased with age and was lowest in the winter; levels were higher in supplement users (vitamin D and/or calcium; p<0.01). Serum PTH did not vary by age or season, and it was lower in supplement users (p<0.01). After excluding 12 men who were outliers for serum 25OHD and PTH, there was no significant correlation between serum 25OHD and PTH (r=-0.05, p=0.3). In multiple adjusted models, serum 25OHD was positively associated with BMD at the hip (p=0.01) and spine (p=0.001). Serum PTH was moderately and inversely associated with BMD at the hip (p=0.04) but not at the spine (p=0.77).

CONCLUSION

We conclude that serum 25OHD is associated with bone health in older, community-dwelling men.

Epidemic influenza and vitamin D

In 1981, R. Edgar Hope-Simpson proposed that a 'seasonal stimulus' intimately associated with solar radiation explained the remarkable seasonality of epidemic influenza. Solar radiation triggers robust seasonal vitamin D production in the skin; vitamin D deficiency is common in the winter, and activated vitamin D, 1,25(OH)2D, a steroid hormone, has profound effects on human immunity. 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the 'oxidative burst' potential of macrophages. Perhaps most importantly, it dramatically stimulates the expression of potent anti-microbial peptides, which exist in neutrophils, monocytes, natural killer cells, and in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection. Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and serological evidence of an immune response in the winter. Vitamin D deficiency predisposes children to respiratory infections. Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D). An interventional study showed that vitamin D reduces the incidence of respiratory infections in children. We conclude that vitamin D, or lack of it, may be Hope-Simpson's 'seasonal stimulus'.

Sunshine is good medicine. The health benefits of ultraviolet-B induced vitamin D production

Most public health statements regarding exposure to solar ultraviolet radiation (UVR) recommend avoiding it, especially at midday, and using sunscreen. Excess UVR is a primary risk factor for skin cancers, premature photoageing and the development of cataracts. In addition, some people are especially sensitive to UVR, sometimes due to concomitant illness or drug therapy. However, if applied uncritically, these guidelines may actually cause more harm than good. Humans derive most of their serum 25-hydroxycholecalciferol (25(OH)D3) from solar UVB radiation (280-315 nm). Serum 25(OH)D3 metabolite levels are often inadequate for optimal health in many populations, especially those with darker skin pigmentation, those living at high latitudes, those living largely indoors and in urban areas, and during winter in all but the sunniest climates. In the absence of adequate solar UVB exposure or artificial UVB, vitamin D can be obtained from dietary sources or supplements. There is compelling evidence that low vitamin D levels lead to increased risk of developing rickets, osteoporosis and osteomaloma, 16 cancers (including cancers of breast, ovary, prostate and non-Hodgkin's lymphoma), and other chronic diseases such as psoriasis, diabetes mellitus, hypertension, heart disease, myopathy, multiple sclerosis, schizophrenia, hyperparathyroidism and susceptibility to tuberculosis. The health benefits of UVB seem to outweigh the adverse effects. The risks can be minimized by avoiding sunburn, excess UVR exposure and by attention to dietary factors, such as antioxidants and limiting energy and fat consumption. It is anticipated that increasing attention will be paid to the benefits of UVB radiation and vitamin D and that health guidelines will be revised in the near future.

A model of the expected occurrence of adverse pregnancy outcomes aboard U.S. Navy ships

The goal of this study was to model the incidence of ectopic pregnancy and spontaneous abortion if pregnant women in the first 20 weeks of gestation were to remain aboard ship while at sea during deployments. Ectopic pregnancies and other pregnancy complications at sea can be life-threatening events. Data sources included shipboard medical departments, an Enlisted Personnel Survey, and the Naval Health Research Center Hospitalized Pregnancy and Women Aboard Ship studies. The overall pregnancy rate was 19 per 100 woman-years (95% confidence interval, 18-20), based on the complement of women assigned to participating ships. If pregnant women routinely were to remain aboard ships at sea during deployments through their first 20 weeks of pregnancy, it is expected that approximately 9 ectopic pregnancies and 40 spontaneous abortions would occur aboard ships at sea.

Calcium and vitamin D. Their potential roles in colon and breast cancer prevention

The geographic distribution of colon cancer is similar to the historical geographic distribution of rickets. The highest death rates from colon cancer occur in areas that had high prevalence rates of rickets--regions with winter ultraviolet radiation deficiency, generally due to a combination of high or moderately high latitude, high-sulfur content air pollution (acid haze), higher than average stratospheric ozone thickness, and persistently thick winter cloud cover. The geographic distribution of colon cancer mortality rates reveals significantly low death rates at low latitudes in the United States and significantly high rates in the industrialized Northeast. The Northeast has a combination of latitude, climate, and air pollution that prevents any synthesis of vitamin D during a five-month vitamin D winter. Breast cancer death rates in white women also rise with distance from the equator and are highest in areas with long vitamin D winters. Colon cancer incidence rates also have been shown to be inversely proportional to intake of calcium. These findings, which are consistent with laboratory results, indicate that most cases of colon cancer may be prevented with regular intake of calcium in the range of 1,800 mg per day, in a dietary context that includes 800 IU per day (20 micrograms) of vitamin D3. (In women, an intake of approximately 1,000 mg of calcium per 1,000 kcal of energy with 800 IU of vitamin D would be sufficient.) In observational studies, the source of approximately 90% of the calcium intake was vitamin D-fortified milk. Vitamin D may also be obtained from fatty fish. In addition to reduction of incidence and mortality rates from colon cancer, epidemiological data suggest that intake of 800 IU/day of vitamin D may be associated with enhanced survival rates among breast cancer cases.

Carpal tunnel syndrome and occupation in U.S. Navy enlisted personnel

The objectives of this study were to (a) describe demographic factors associated with high rates of carpal tunnel syndrome (CTS), cubital tunnel syndrome, and other neuritis of the arm and hand, and (2) identify the high-risk occupations associated with these disorders in the Navy. Computerized records of first hospitalizations of all active-duty Navy-enlisted personnel were searched for all cases of CTS, cubital tunnel syndrome, and other neuritis of the arm and hand (ICD-9 CM codes 354.0-354.9) during 1980-1988. There were 1039 first hospitalizations (including 493 cases of CTS) for all neuritis of the arm and hand in 4095708 person-years in men and 186 first hospitalizations (including 90 cases of CTS) in 365668 person-years in women. Incidence rates of hospitalized cases with CTS rose with age for both sexes. Rates in white women were approximately three times those in white men (p < .0001), but rates in black women were not significantly different from those in black men. Rates of cubital tunnel syndrome also increased with age in both sexes and were higher in white women than white men (p < .05). Occupations with significantly high standardized incidence ratios (p < .05) for CTS in men included aviation-support equipment technician, engineman, hull-maintenance technician, boatswain's mate, and machinist's mate. In women, occupations with significantly high standardized incidence ratios included boatswain's mate, engineman, hospital corpsman, ocean-systems technician, and personnelman. Several occupations for each sex had significantly high standardized incidence ratios for cubital tunnel syndrome, with high rates in hospital corpsmen of both sexes (p < .05). Gender and race differences according to occupation did not account for the occupations at highest risk. Further research is needed to determine the extent to which CTS and related disorders could be prevented by modifying the motions currently performed in occupations with the highest standardized incidence ratios.

Long-term health outcomes and medical effects of torture among US Navy prisoners of war in Vietnam

OBJECTIVE

To characterize incidence of illnesses and injuries from 1979 to 1993 in former naval aviator prisoners of war (POWs) from the Vietnam War and a comparison group of naval aviators from the same war.

DESIGN

Cohort analytic study.

SETTING

A US Navy primary care clinic.

PARTICIPANTS

Volunteer sample consisting of 70 former naval aviator POWs (white men, aged 47 to 69 years in 1993) and a comparison group of 55 naval aviators who served in Vietnam but were not POWs, matched on race, age, marital status, education, rank, year of entry into the navy, and pilot status. Subjects participated in an annual health screening program. This study reports data sampled on a biennial basis from subjects screening both in 1979 and 1993.

MAIN OUTCOME MEASURE

Medically diagnosed incidence of illness and injury based on a standard protocol.

RESULTS

POWs had higher incidence rates than the comparison group did of disorders of the peripheral nervous system (relative risk [RR], 8.4; 95% confidence interval [CI], 2.7-25.9; P<.001), joints (RR, 1.5; 95% CI, 1.2-2.0; P<.006), and back RR, 1.8; 5% CI, 1.0-3.0; P<.037). These findings also were statistically significant according to Kaplan-Meier survival analyses that included 131 (95%) of 138 POWs and 115 (83%) of the 138 members of the comparison group. Survival analyses revealed that, in addition to these disorders, POWs had higher hazard rates of peptic ulcer (P<.01).

CONCLUSIONS

During captivity, ropes, ratchet handcuffs, leg irons, or stocks were used to put tightly constrictive pressure around the extremities of POWs as a means of torture, resulting in painful ischemia and subsequent neuropathies. Being a former POW was associated with increased cumulative incidence rates of chronic disorders of the peripheral nervous system, joints, and back and an increased hazard rate of peptic ulcer.

Western blot banding patterns of HIV rapid progressors in the U.S. Navy Seropositive Cohort: implications for vaccine development. Navy Retroviral Working Group

Although human immunodeficiency virus (HIV) infection is progressive, the rate of decline in CD4+ lymphocyte counts varies. The role of immune system components in limiting HIV infection has yet to be defined, but a previous report on the U.S. Navy HIV Seropositive Cohort reported that strong reactivity in the anti-p55 (core precursor), p24 (core) and p53 (reverse transcriptase) Western blot bands was associated with higher CD4+ lymphocyte counts at the first clinical evaluation for HIV. The previous report examined the cross-sectional association between Western blot banding patterns and initial CD4+ lymphocyte counts. This report examines the association between these banding patterns in individuals who progressed rapidly as compared with patterns of patients who did not, based on their trends in repeated CD4+ lymphocyte counts as a marker of progression. Rapid and slower progressors were identified from a cohort of 3414 Navy and Marine Corps personnel who had a first positive HIV Western blot during 1986-1991. For purposes of this study, rapid progressors were defined as individuals whose CD4+ lymphocyte counts declined to < 500 cells/mm3 within 1 year of seroconversion. A total of 325 individuals met these criteria. A comparison group of 63 slower progressors also was identified; this group consisted of those whose CD4+ lymphocyte counts remained at > or = 500 cells/mm3 for a minimum of 5 years of follow-up after their first positive Western blot. Rapid progressors were slightly younger than slower progressors and were more likely to be never married but did not differ significantly from slower progressors in race or sex. Rapid progressors had weaker reactivity in the anti-p55 core precursor (P < 0.0001), p15 core (P < 0.01), gp41 transmembrane (P < 0.01) and p31 endonuclease (P < 0.05) bands on the Western blot. The odds ratio for rapid progressor status associated with weak or absent reactivity was 7.8 in the anti-p55 band and ranged from 2.0 to 3.2 in the anti-p31, p15, and gp41 bands. These associations remained significant after adjustment for age, race, and sex. The p55 association persisted in repeated Western blots during routine clinical evaluation during a period of 5 years after the first positive Western blot. It was concluded that several possible explanations may account for the weaker reactivity of rapid progressors: (i) weak anti-p55 reactivity might have been a marker of early immune system damage; (ii) high concentrations of p55 or related proteins in the serum may have bound the available anti-p55 antibodies in rapid progressors, making them difficult to identify on the Western blot; or (iii) lack of anti-p55, p15, gp41, or p31 reactivity might have allowed more rapid progression.

Sunlight, vitamin D, and ovarian cancer mortality rates in US women

BACKGROUND

In general, ovarian cancer incidence and mortality is higher in northern than southern latitudes. This ecologic study tests the hypothesis that vitamin D produced in the skin from sunlight exposure may be associated with a protective action in ovarian cancer mortality.

METHODS

The association between average annual sunlight energy and age-specific ovarian cancer mortality rates in counties containing the 100 largest US cities was evaluated for 1979-1988. Simple linear regression was performed by decade using sunlight and ozone as independent variables and ovarian cancer rates as the dependent variable. Multiple regression was used to adjust for ozone and sulphur dioxide, since these atmospheric components may absorb ultraviolet light.

RESULTS

Fatal ovarian cancer in these areas was inversely proportional to mean annual intensity of local sunlight in a univariate analysis (P = 0.0001), and in a regression adjusted for air pollution (P = 0.04). The association was also seen when restricted to 27 major urban areas of the US; however, probably due to a small sample size, this statistic did not reach significance.

CONCLUSIONS

This ecologic study supports the hypothesis that sunlight may be a protective factor for ovarian cancer mortality.

Specific western blot bands are associated with initial CD4+ lymphocyte counts in human immunodeficiency virus seroconverters. The Navy HIV Working Group

The Western blot is the most widely used confirmatory test for determining human immunodeficiency virus (HIV) seropositivity. Specific bands in the Western blot indicate antibody responses to various portions of HIV or its precursors, and each is assigned a score from 0 to 3+. While the precise role of humoral antibody responses has not been fully established, specific antibody responses might influence the course of HIV infection. This study investigated the association between antibody reactivity to nine principal Western blot bands and initial CD4+ counts among 877 Navy and Marine Corps personnel during 1988 to 1991. Multiple regression was used to evaluate the strength and significance of the associations and to adjust for age and estimated duration of infection. Strong antibody responses to the p24 core (P < 0.05), p53 reverse transcriptase (P < 0.005), and p55 core precursor (P < 0.0001) antigens were associated with higher initial CD4+ counts, with 33 to 48 additional cells/mm3 associated with each unit increase in the Western blot score, according to a multiple regression analysis which controlled for age and duration of infection (maximum 24 months). By contrast, antibodies to the gp41 transmembrane antigen (P < 0.0001) were associated with lower initial CD4+ counts. Each unit increase in the gp41 band was associated with 76 fewer CD4+ cells/mm3. A negative association was also observed for the gp160 envelope precursor antigen, with each unit increase in reactivity associated with 51 fewer CD4+ cells, although this association was not statistically significant (P = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of association of human immunodeficiency virus seroconversion with visits to foreign ports in US Navy personnel

BACKGROUND

The US Navy visits ports on all continents and many islands of the world, many of which are reported to have a high endemicity of human immunodeficiency virus (HIV) infection. The objective of this study was to determine whether visits to foreign ports by active-duty navy personnel were associated with increased risk of HIV infection.

METHODS

The Naval Health Research Center in San Diego, Calif, maintains records of all HIV enzyme-linked immunosorbent assay and Western blot tests given in the navy. This information, along with career histories and ship movement data, was used in a nested case-control design to examine the relationship between visits to the 100 foreign ports most frequently visited by the navy and risk of HIV seroconversion. All visits to a port and total time in each port during the study period were examined. A total of 813 seroconverters were matched to 6993 seronegative active-duty controls by age, race, sex, occupational group, home port, and year of test.

RESULTS

Estimated relative risks of seroconversion associated with visits to foreign ports showed no statistically significant excess risk of HIV infection for navy personnel after visits to any foreign port.

CONCLUSIONS

These results do not imply that an individual's risk of acquisition of HIV would be less in a foreign port if the individual engaged in high-risk activity there. Rather, they imply that despite the mobility of the US Navy and the large variation in HIV seroprevalence rates throughout the world, navy personnel generally do not appear to be acquiring HIV infections abroad.

Incidence of insulin-dependent diabetes mellitus in young adults: experience of 1,587,630 US Navy enlisted personnel

First hospitalizations (n = 1,293) for diabetes mellitus between 1974 and 1988 were used as a surrogate for insulin-dependent diabetes mellitus incidence among 17-34-year-old US Navy enlisted personnel followed for 6,077,856 person-years. In the 15-year period, the overall incidence of insulin-dependent diabetes mellitus was 21.3 per 100,000 person-years. Incidence did not differ significantly by sex, but was higher for blacks than whites (28.4 vs. 20.2 per 100,000 person-years, respectively; p < 0.05). Incidence increased with age threefold for white men and fivefold for black men (p < 0.05) between the ages of 17-19 and 30-34 years.

Geographic variation in human immunodeficiency virus seroconversion rates in the U.S. Navy

The Navy population is centered around 19 U.S. home ports and several inland duty stations. This is a study of variation in human immunodeficiency virus (HIV) seroconversions in Navy enlisted men by location in the United States, based on 949,570 enzyme-linked immunosorbent assays and 812 seroconversions during 1987-90. Seroconversion rates were higher in personnel in San Francisco (p = 0.0004), Washington, D.C. (p = 0.001), and Orlando, FL (p = 0.04) than in other areas. They were lower in Charleston, SC, New London, CT, Seattle; and Brunswick, ME (p < 0.05). Black men had triple the seroconversion rate of all other men (p < 0.0001). After adjustment for race, age, marital status, and occupation, risk of seroconversion remained high in San Francisco (p = 0.02) and Orlando (p = 0.03). The risk of seroconversion in San Francisco was twice that of other areas in a cohort that did not change location (p = 0.01). In contrast to declining trends overall in the Navy, rates did not decrease in Washington, D.C., a result consistent with previous calculations indicating a delayed second wave of HIV infection in the region.

Rising trends in melanoma. An hypothesis concerning sunscreen effectiveness

Incidence rates of melanoma have risen especially steeply since the mid-1970s. The two principal strategies for reduction of risk of melanoma and other skin cancers are sun avoidance and use of chemical sunscreens. Rising trends in the incidence of and mortality from melanoma have continued since the 1970s and 1980s, when sunscreens with high sun protection factors became widely used. Commonly used chemical sunscreens block ultraviolet B (UVB) but are virtually transparent to ultraviolet A (UVA), which makes up 90 to 95% of ultraviolet energy in the solar spectrum. Because sunscreens prevent erythema and sunburn, and inhibit accommodation of the skin to sunlight, their use may permit excessive exposure of the skin to portions of the solar spectrum other than UVB. If melanoma and basal cell carcinoma are initiated or promoted by solar radiation other than UVB, as laboratory data suggest, then UVB sunscreens might not be effective in preventing these cancers, and sunscreen use might increase the risk of their occurrence. Alternative explanations for the rapid rise in the incidence and mortality rates of melanoma, such as changes in patterns of recreational sun exposure, are discussed. Traditional means of limiting overexposure to the sun, such as wearing of hats and adequate clothing and avoidance of prolonged sunbathing, may be more prudent than reliance on chemical sunscreens.

Sex hormones and postmenopausal breast cancer: a prospective study in an adult community

Few studies have examined the role of endogenous sex hormones in breast cancer, and to the authors' knowledge, only two have done so prospectively. The authors report here the results of a prospective study based on an available bank of previously analyzed plasma collected in 1972-1974 from 442 women aged 50-79 years in Rancho Bernardo, California. These women were followed for 12-15 years, during which time 42 cases of breast cancer were identified: 15 incident cases diagnosed 1 year or more after baseline, 18 prevalent cases diagnosed earlier than 1 year after baseline, and 9 cases with unknown dates of onset. No apparent trends in plasma levels of sex hormones or sex hormone-binding globulin and incidence or prevalence of breast cancer were observed. Mean crude and age-adjusted plasma hormone levels at baseline (in pg/ml) for incident cases, total cases, and noncases, respectively, were: androstenedione: 647, 638 +/- 328 (standard deviation); 626, 620 +/- 245; and 664, 664 +/- 291; testosterone: 254, 258 +/- 120; 238, 241 +/- 153; and 262, 261 +/- 143; estrone: 37, 38 +/- 18; 35, 35 +/- 15; and 37, 37 +/- 17, and estradiol: 13, 13 +/- 7; 15, 15 +/- 8; and 15, 15 +/- 9. For sex hormone-binding globulin, mean crude and age-adjusted levels at baseline (nM) were 35 and 36 +/- 33 for incident cases; 31 and 31 +/- 25 for total cases; and 29 and 29 +/- 21 for noncases. Cox proportional hazards multiple regression showed no associations with breast cancer after simultaneous adjustment for age, body mass index, and cigarette smoking.

Can colon cancer incidence and death rates be reduced with calcium and vitamin D?

It was proposed in 1980 that vitamin D and calcium could reduce the risk of colon cancer. This assertion was based on the decreasing gradient of mortality rates from north to south, suggesting a mechanism related to a favorable influence of ultraviolet-induced vitamin D metabolites on metabolism of calcium. A 19-y prospective study of 1954 Chicago men found that a dietary intake of greater than 3.75 micrograms vitamin D/d was associated with a 50% reduction in the incidence of colorectal cancer, whereas an intake of greater than or equal to 1200 mg Ca/d was associated with a 75% reduction. Clinical and laboratory studies further support these findings. A nested case-control study based on serum drawn from a cohort of 25,620 individuals reported that moderately elevated concentrations of 25-hydroxyvitamin D, in the range 65-100 nmol/L, were associated with large reductions (P less than 0.05) in the incidence of colorectal cancer.

Sunlight and breast cancer incidence in the USSR

Epidemiological and laboratory evidence suggest that vitamin D may play a role in reducing risk of breast cancer. Lack of exposure to ultraviolet sunlight can increase the prevalence of vitamin D deficiency, and may place some populations at higher risk of breast cancer. The association between total average annual sunlight energy striking the ground and age-adjusted breast cancer incidence rates in the USSR was evaluated. Breast cancer had a threefold range of incidence. Sunlight levels varied from 210 to 400 calories per cm2 per day. A statistically significant negative association was found between breast cancer incidence rates and total sunlight levels (R = -0.75, p = 0.001). The slope of the regression line corresponded to two additional cases per 100,000 per year for each reduction of 35 calories per cm2 of sunlight. The pattern of increased breast cancer incidence in regions of low solar radiation in the USSR is consistent with the geographical pattern seen for breast cancer mortality in the US and worldwide. A positive relationship between socioeconomic status and breast cancer incidence was also present in the Soviet Union, based on an approximate socioeconomic measure, the number of doctors per 1000 population (R = +0.89, p = 0.0001). The possibility that correlates of socioeconomic status, such as dietary, ethnic, or behavioural factors, could account for the association is discussed.

Geographic variation in breast cancer mortality in the United States: a hypothesis involving exposure to solar radiation

Epidemiologic and laboratory evidence suggests that vitamin D may play a role in reducing breast cancer risk. Lack of exposure to ultraviolet sunlight can increase the prevalence of vitamin D deficiency. This deficiency may place some populations at higher risk for breast cancer. The association between total average annual sunlight energy striking the ground and age-adjusted breast cancer mortality rates in 87 regions of the United States was evaluated. Annual age-adjusted mortality rates for breast cancer varied over a 1.8-fold range, from 17-19 per 100,000 in the South and Southwest United States to 33 per 100,000 in the Northeast; the overall U.S. rate was 27.3 per 100,000. Risk of fatal breast cancer in the major urban areas of the United States was inversely proportional to intensity of local sunlight (r = -0.80, P = 0.0001); multiple regression with stratospheric ozone measurements, r = -0.82, P = 0.0001). Vitamin D from sunlight exposure may be associated with low risk for fatal breast cancer, and differences in ultraviolet light reaching the United States population may account for the striking regional differences in breast cancer mortality. The ecological nature of this study is emphasized, and the possibility that an indirect association with dietary and socioeconomic factors could explain these findings is discussed.

Occupational sunlight exposure and melanoma in the U.S. Navy

Melanoma is the second most common cancer, after testicular cancer, in males in the U.S. Navy. A wide range of occupations with varying exposures to sunlight and other possible etiologic agents are present in the Navy. Person-years at risk and cases of malignant melanoma were ascertained using computerized service history and inpatient hospitalization files maintained at the Naval Health Research Center. A total of 176 confirmed cases of melanoma were identified in active-duty white male enlisted Navy personnel during 1974-1984. Risk of melanoma was determined for individual occupations and for occupations grouped by review of job descriptions into three categories of sunlight exposure: (1) indoor, (2) outdoor, or (3) indoor and outdoor. Compared with the U.S. civilian population, personnel in indoor occupations had a higher age-adjusted incidence rate of melanoma, i.e., 10.6 per 100,000 (p = .06). Persons who worked in occupations that required spending time both indoors and outdoors had the lowest rate, i.e., 7.0 per 100,000 (p = .06). Incidence rates of melanoma were higher on the trunk than on the more commonly sunlight-exposed head and arms. Two single occupations were found to have elevated rates of melanoma: (1) aircrew survival equipmentman, SIR = 6.8 (p less than .05); and (2) engineman, SIR = 2.8 (p less than .05). However, there were no cases of melanoma or no excess risk in occupations with similar job descriptions. Findings on the anatomical site of melanoma from this study suggest a protective role for brief, regular exposure to sunlight and fit with recent laboratory studies that have shown vitamin D to suppress growth of malignant melanoma cells in tissue culture. A mechanism is proposed in which vitamin D inhibits previously initiated melanomas from becoming clinically apparent.

Incidence of leukemia in occupations with potential electromagnetic field exposure in United States Navy personnel

Leukemia is the fourth most commonly occurring cancer in the United States population between the ages of 17 and 34 years, an age group heavily represented in the US Navy. Historical computerized military career records maintained at the Naval Health Research Center, San Diego, California, were used to determine person-years at risk (total, 4,072,502 person-years) by demographic characteristics and occupation for active-duty naval personnel during 1974-1984. Computerized inpatient medical records were searched for first hospitalizations for leukemia. Cases of leukemia (n = 102) were verified by using pathology reports or Navy Medical Board or Physical Evaluation Board findings. For comparisons, age-adjusted incidence rates and standardized incidence ratios were calculated by using rates for the US population provided by the Surveillance, Epidemiology, and End Results program of the National Cancer Institute. The overall age-adjusted incidence rate of leukemia in active-duty naval personnel was found to be very close to that of the Surveillance, Epidemiology, and End Results program population (6.0 vs. 6.5 per 100,000 person-years). Only one occupation, electrician's mate, emerged with a borderline statistically significant excess risk of leukemia (standardized incidence ratio compared with the Surveillance, Epidemiology, and End Results program population = 2.4, 95% confidence interval 1.0-5.0). This finding is intriguing in the light of several studies showing an excess risk of leukemia associated with exposure to electromagnetic fields.

Serum 25-hydroxyvitamin D and colon cancer: eight-year prospective study

Blood samples taken in 1974 in Washington County, Maryland, from 25 620 volunteers were used to investigate the relation of serum 25-hydroxyvitamin D (25-OHD) with subsequent risk of getting colon cancer. 34 cases of colon cancer diagnosed between August, 1975, and January, 1983, were matched to 67 controls by age, race, sex, and month blood was taken. Risk of colon cancer was reduced by 75% in the third quintile (27-32 ng/ml) and by 80% in the fourth quintile (33-41 ng/ml) of serum 25-OHD. Risk of getting colon cancer decreased three-fold in people with a serum 25-OHD concentration of 20 ng/ml or more. The results are consistent with a protective effect of serum 25-OHD on colon cancer.

Acid haze air pollution and breast and colon cancer mortality in 20 Canadian cities

Sulfur dioxide absorbs ultraviolet light in the region of the spectrum which is most active in forming vitamin D on the skin. Sulfate particles reflect light at this wavelength. High concentrations of these pollutants (acid haze) may lead to vitamin D deficiencies in exposed populations. Epidemiologic and laboratory evidence suggests that vitamin D plays a role in reducing risk of colon and breast cancer. We examined the association between sulfur dioxide and ultraviolet-light-blocking aerosols in 20 Canadian cities, and age-adjusted breast and colon cancer mortality rates in the census divisions encompassing these cities. Statistically significant positive associations were found between these two measures of air pollution and age-adjusted mortality rates for colon cancer in women (multiple r = +.74, p = 0.003), and men (multiple r = +.61, p = 0.03), and breast cancer in women (multiple r = +.69, p = 0.007). Mortality rates for all other reported cancer sites were also examined, and no statistically significant positive associations were found consistently in both sexes. The ecological nature of this study is emphasized, and the possibility that an indirect association could explain these findings is discussed.

Declining trends in mortality from cerebrovascular disease at ages 10-65 years: a test of validity

Recent reports of declining trends in mortality rates from cerebrovascular disease are based on underlying cause of death as stated on the death certificate, and may contain inaccuracies because death certificates are often completed without reference to all information in medical records, and because of changes in coding conventions and diagnostic fashion. This is a report of trends in mortality rates from cerebrovascular disease in Baltimore, Md., during 1950-1970 using data validated by reference to individual medical records from 19 hospitals. Overall accuracy of death certificate diagnoses did not change markedly during the study period. Death rates from subarachnoid hemorrhage increased in white women, but decreased in white men and in nonwhites of both sexes. Death rates from other cerebrovascular diseases declined in most sex and color groups, a result which cannot be attributed to errors in death certificate diagnoses. The increasing rates of subarachnoid hemorrhage observed in white women deserve further attention.

Non-Hodgkin's lymphomas in U.S. Navy personnel

Non-Hodgkin's lymphomas are one of the most commonly occurring cancers in the age groups heavily represented in the U.S. Navy. The Navy has a wide range of potential occupational exposures. This study was initiated to identify any occupational associations of non-Hodgkin's lymphomas that may adversely affect naval readiness. The objective of this study was to compare the incidence of non-Hodgkin's lymphomas in U.S. Navy active duty enlisted personnel during the period 1974-1983 with the general U.S. population, and to assess if risk varied by naval occupation or length of service. The Naval Health Research Center's computer-based disease registry was used to conduct a prospective study of all white U.S. Navy enlisted men during 1974-1983 to test for the existence of any short-term risk possibly due to occupation. Men in 80 occupations, ranging from clerk to journalist to machinist and boiler operator were observed for 3,704,864 person-years; mean length of service was 5.1 yr, but 19% of person-years were contributed by men who had served at least 11 yr. Incident cases of non-Hodgkin's lymphomas were identified and verified using Medical Board findings or review of original medical records. Average annual age-specific and age-adjusted incidence rates were calculated. Examination of pathology records and medical review boards confirmed 68 cases of non-Hodgkin's lymphomas. The annual age-adjusted incidence rate per 100,000 person-years in Navy men was significantly lower than in the U.S. Surveillance, Epidemiology, and End Results (SEER) population, probably due to screening and other selection factors associated with Navy service that result in a healthy worker effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Testicular cancer in US Navy personnel

Age-adjusted and age-specific incidence rates of testicular cancer in US Navy personnel did not differ significantly from those of the US population, and age-adjusted incidence rates did not increase with length of service in the Navy. There was a group of three occupations, however, which involved duties similar to those of the civilian occupation of automobile mechanic, and which had a significantly elevated age-adjusted rate of testicular cancer compared with the US population and the total Navy population. These occupations were aviation support equipment technician, engineman, and construction mechanic. All involve maintenance of internal combustion engines and exposure to the attendant lubricants, solvents, paints, and exhausts.

Coffee and pancreatic cancer in a rural California county

In a study of the risk of fatal pancreatic cancer according to intake of regular and decaffeinated coffee, cases (N = 30) and controls (N = 47) were identified from death certificates and matched for age (+/- 5 years), sex, ethnicity, and date of death (+/- 5 years). Telephone interviews were completed with survivors of about 80% of both groups. In smokers, the relative risk for high (3 + cups) versus low (<3 cups) intake of regular coffee was 4.3 (P < .05), and high verus low decaffeinated coffee, 5.5 (P < .05). In nonsmokers, neither type of coffee influenced the risk. Mean daily intakes of alcohol and cigarettes were virtually identical in cases and controls, although cases had accumulated nonsignificantly more pack-years. Intakes of regular and decaffeinated coffee were uncorrelated, and the smoking-coffee interaction could not be readily explained by recall bias. If coffee intake increases the risk of pancreatic cancer, the mechanism could depend heavily on smoking.

Hodgkin's disease in the US Navy

Hodgkin's disease incidence has an early peak in young adulthood. The US Navy maintains computerized career history and hospitalization information for one of the largest defined populations of young adults available for prospective studies. There were approximately 2.3 million person-years at risk in white male enlisted personnel involved in more than 80 occupations in the Navy from 1974-79. During this period 88 incident cases were identified. Navy age-adjusted incidence rates of Hodgkin's disease did not differ significantly from US population rates. There was a slight, but not significant, increased incidence with increasing length of Navy service. One occupation, machinists' mate, had about double the risk of Hodgkin's disease as the entire Navy (SIR = 2.3, p = 0.004) and the US population (SIR = 1.8, ns). Probable exposures of machinists' mates include: volatile solvents, metal dusts and, possibly, ionizing radiation. Further studies are needed, however, to clarify this association.

Trends in incidence rates of ulcerative colitis and Crohn's disease

Between 1960 and 1979, three studies were conducted in the Baltimore Standard Metropolitan Statistical Area to ascertain the incidence rates of first hospitalizations for ulcerative colitis and Crohn's disease. The age-adjusted rates per 100,000 population for the 1977-1979 survey for ulcerative colitis in white and nonwhite males and females were 2.92, 1.79, 1.29, and 2.90, respectively; the Crohn's disease rates were 3.39, 3.54, 1.29, and 4.08, respectively. In Baltimore the age-adjusted rate for Crohn's disease has increased to exceed the ulcerative colitis rate for whites of both sexes and nonwhite females. The ulcerative colitis and Crohn's disease rates for nonwhite males are similar. The rate for white males exceeds that for nonwhite males for both ulcerative colitis and Crohn's disease, but the converse is true for females. Females have higher rates than males for Crohn's disease in both color groups and for ulcerative colitis among nonwhites. White ulcerative colitis rates are higher for males than for females. From the first to the second surveys, the white male and female rates for ulcerative colitis converge with increasing male and decreasing female rates, but then both decline from the second to the third surveys. For Crohn's disease, the age-adjusted rates increased for whites of both sexes and nonwhite females from the first to second surveys. The Crohn's disease rates appeared to stabilize for whites of both sexes between the second and present surveys, but they increased for nonwhites of both sexes. Trends in age-adjusted rates for other areas are also discussed.

Incidence rates of ulcerative colitis and Crohn's disease in fifteen areas of the United States

A study was carried out during 1973 to determine the incidence of first hospitalizations for ulcerative colitis and Crohn's disease in 15 areas of the United States, including communities of widely varied size, climatic, ethnic, racial, and socioeconomic characteristics. The following descriptions apply to incidence rates per 100,000 population for the aggregate of the 15 areas. Ulcerative colitis had a bimodal age distribution in white males (with peaks at ages 20-29 and 70-79 yr) and females (with peaks at ages 30-39 and 70-79 yr). Crohn's disease had a bi- or trimodal age distribution in white males (with peaks at ages 20-29, 50-59, and 70-79 yr) and females (with peaks at ages 20-29, 50-59, and 70-79 yr). The age, sex, and geographic distributions that were observed in this study may have important etiologic implications.

Do sunlight and vitamin D reduce the likelihood of colon cancer?

It is proposed that vitamin D is a protective factor against colon cancer. This hypothesis arose from inspection of the geographic distribution of colon cancer deaths in the U.S., which revealed that colon cancer mortality rates were highest in places where populations were exposed to the least amounts of natural light--major cities, and rural areas in high latitudes. The hypothesis is supported by a comparison of colon cancer mortality rates in areas that vary in mean daily solar radiation penetrating the atmosphere. A mechanism involving cholecalciferol (vitamin D3) is suggested. The possibility that an ecological fallacy or other indirect association explains the findings is explored.