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.

Could ultraviolet B irradiance and vitamin D be associated with lower incidence rates of lung cancer?

BACKGROUND: This study examines whether insufficient ultraviolet B (UVB) irradiance, a marker of vitamin D inadequacy, might contribute to lung cancer incidence. METHODS: The association of latitude and UVB irradiance with age-adjusted incidence rates of lung cancer in 111 countries was investigated. Independent associations with UVB irradiance, cloud cover, anthropogenic aerosols, and cigarette smoking, were assessed using multiple regression. RESULTS: Latitude was positively related to incidence rates in men (R(2) = 0.55, p<0.01) and women (R(2) = 0.36, p<0.01). In men, cigarette consumption (p<0.001) was positively related to risk, whereas UVB irradiance was inversely associated (p = 0.003). There were positive associations with UVB absorbers, in particular cloud cover (p = 0.05) and aerosol optical depth (p = 0.005). The R(2) for the model was 0.78 (p<0.001). UVB irradiance was also inversely associated with incidence rates in women (p = 0.0002), whereas cigarette consumption (p<0.001), total cloud cover (p = 0.02) and aerosol optical depth (p = 0.005) were positively associated. The R(2) for the model was 0.77 (p<0.001). CONCLUSIONS: Lower levels of UVB irradiance were independently associated with higher incidence rates of lung cancer in 111 countries.

Accidents and injuries among U.S. Navy crewmembers during extended submarine patrols, 1997 to 1999.

Accidents and injuries, the most common cause of morbidity in military populations, result in a significant number of work days lost each year and account for 75% of all active duty deaths. Rates of accidents and injuries during U.S. Navy submarine deployments have not been evaluated previously. A database designed to monitor the health of submarine crew-members was used to examine the rates and causes of accidents among deployed crewmembers aboard 196 submarine patrols between 1997 and mid 1999. The most common category of injuries was open wounds, followed by sprains and strains, contusions, superficial injuries, burns, and others. Rates of accidents and injuries decreased with increasing age and duration of military service. Among submariners working in supply departments, the rates were more than two times those of crewmembers working in other departments. Based on these data, among a submarine crew of 100 men at sea for 100 days, approximately four to five accidents or injuries might be expected and would result in an average of about 2 days of light or no duty per injury. Rates of accidents and injuries were very low; however, focused safety training could reduce rates among younger and less experienced crewmembers as well as among those working in particular areas of the submarine.

Contraceptive use and attitudes toward family planning in Navy enlisted women and men.

Little is known about the contraceptive behavior and beliefs of Navy personnel. Nevertheless, the Navy, in its role as primary medical provider for its personnel, needs to know whether sailors have access to effective birth control and are sufficiently informed about contraception to make wise choices. As part of the Women Aboard Navy Ships Comprehensive Health and Readiness Project conducted at the Naval Health Research Center in San Diego, California, contraceptive use and attitudes toward family planning were assessed through a survey administered to 714 enlisted women and 665 enlisted men on 15 ships. Contraceptive use was not related to gender, age, marital status, pay grade, race, or education. More favorable family planning attitudes were related to contraceptive use. Women and men differed in their attitudes toward family planning, with women's responses more positive than men's. The results highlight the need for research focusing on the effect of attitudes on contraceptive behavior.

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.

A method for monitoring the health of US Navy submarine crewmembers during periods of isolation.

BACKGROUND: With the expansion of the manned space program, an essential consideration in planning is the medical support necessary for long-term missions. Information on analogous populations serving in isolated and/or contained environments may be useful in predicting health risks for astronauts. METHODS: The present study evaluates rates of health events that occur in a highly screened, healthy military population during periods of isolation. A centralized database was designed to collect medical encounter data from U.S. Navy submarines and contains demographic information, crew rosters for each patrol, medical encounter notes, accident reports, medical evacuation reports, vital signs and laboratory data. The population included in the present analysis is composed of crewmembers aboard 136 submarine patrols between January 1, 1997 and December 31, 1998. RESULTS: A total of 2,044 initial visits to medical staff and 973 re-visits for the same condition were recorded during these patrols. Potentially mission-impacting medical events reported among crewmembers were rare (i.e., among a crew of 10 individuals, only 1-2 medical events would be expected to occur during a 100 d-mission). The most common category of medical events was injury, followed by respiratory illnesses (URIs), skin problems (minor infections, ingrown toenail), symptoms and ill-defined conditions, digestive disorders, infectious conditions, sensory organ problems (ear and eye), and musculoskeletal conditions.

The association of behavior and lifestyle factors with menstrual symptoms.

The present study examines the association of obesity, cigarette smoking, alcohol consumption, and exercise with the prevalence of menstrual cycle disorders among 2912 women aboard U.S. Navy ships. Self-administered surveys obtained information on weight, height, cigarette smoking, alcohol consumption, and exercise. Participants also indicated whether they experienced cramps or pain during their period requiring medication or time off work, bleeding between periods, excessive frequency of periods, heavy periods, periods lasting for longer than a week, scanty menstrual flow, and irregular periods during the past 90 days. Women ranged in age from 18 to 49 years, with an average of 26 years. After adjustment for age, race, and pay grade, current cigarette smoking was associated with increased risk of all menstrual symptoms and cycle disorders. As compared with nonsmokers, current smokers were at increased risk of cramps or pain requiring medication or time off work (odds ratio [OR] = 1.13, 95% confidence interval [CI] = 1.03, 1.25), bleeding between periods (OR = 1.22, CI = 1.09, 1.38), excessive frequency of periods (OR = 1.33, CI = 1.17, 1.51), heavy periods (OR = 1.17, CI = 1.06, 1.29), periods lasting longer than a week (OR = 1.31, CI = 1.16, 1.48), scanty flow (OR = 1.13, CI = 1.01, 1.29), and irregular periods (OR = 1.14, CI = 1.05, 1.24). Obesity, exercise, and alcohol consumption did not show consistent associations with menstrual symptoms or cycle disorders. Logistic regression models that included age, race, pay grade, and all behavioral and lifestyle variables indicated only cigarette smoking was associated with an increased risk of bleeding between periods (OR = 1.33, CI = 1.05, 1.68), excessive frequency of periods (OR = 1.38, CI = 1.21, 1.58), periods lasting longer than a week (OR = 1.45, CI = 1.13, 1.84), and irregular periods (OR = 1.25, CI = 1.05, 1.47). Although the lifestyle factors are all potentially modifiable, results suggest that only interventions targeted at smoking cessation might be useful in reducing the prevalence of menstrual symptoms, cycle disorders, and time lost from work.

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.

Testicular cancer and Persian Gulf War service.

We studied whether regular, active-duty servicemen deployed to the Persian Gulf War were at increased risk of testicular cancer compared with nondeployed Gulf War-era servicemen from August 1991 through March 31, 1996, using a Cox proportional hazards model for survival analysis with covariates. Race was an important predictor of hospitalization for testicular cancer [rate ratio (RR) = 0.19; 95% confidence interval (CI) = 0.12-0.29 for blacks, and RR = 0.59; 95% CI = 0.39-0.91 for Hispanics, other, and unknown (combined), relative to whites]. Age effects were modest (RR = 1.19; 95% CI = 0.91-1.56 for those of ages 22-25 years, and RR = 1.24; 95% CI = 0.96-1.59 for those of ages 26-31 years, compared with those of ages 17-21 years). Risk also varied with occupation (RR = 1.56; 95% CI = 1.23-2.00 for those in electronic equipment repair; RR = 1.26; 95% CI = 1.01-1.58 for those in electrical/mechanical repair; and RR = 1.42; 95% CI = 0.93-2.17 for those in construction-related trades, compared with those in other occupations). Deployment status was not important (RR = 1.05; 95% CI = 0.86-1.29 for the deployed compared with the nondeployed). There was an increase in testicular cancer in the deployed group in the immediate postwar period that was consistent with a previous report of a standardized RR of 2.12; 95% CI = 1.11-4.02 (compared with the nondeployed group) in the last 5 months of 1991, but by 4 years after the end of deployment, the cumulative risks for the two groups were not different. An additional analysis suggested that the immediate postwar increase in the deployed was likely due to regression to the mean after a healthy serviceman selection effect for deployment and the deferment of care during deployment.

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.

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.

Detection of diverse HIV-1 genetic subtypes in the USA.

Of the nine genetic subtypes of HIV-1 that exist world wide, subtype B predominates in North America and Europe. Thus, most knowledge about HIV-1 and most vaccine development efforts are based on subtype B viruses. We document here the detection of HIV-1 subtypes A, D, and E in five US servicemen who acquired these non-subtype-B infections during overseas deployments. The dispersal of diverse HIV-1 subtypes into regions of the world with previously restricted genetic diversity may have important implications for the epidemiology of the epidemic and for the design and implementation of vaccine trials.

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)

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.

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.