Longitudinal changes in adverse effects reporting in multiple dietary supplement classifications: The US military dietary supplement use study.

Over 70% of United States military service members (SMs) regularly use dietary supplements (DSs) and about 18% have reported adverse effects (AEs) associated with use. This investigation examined longitudinal changes in AEs reporting among DS users. On two separate occasions 1.3 ± 0.2 years apart (mean ± standard deviation), 5778 SMs completed identical questionnaires on DS use and associated AEs. Among SMs reporting DS use ≥1 time/week, ≥1 AE was reported by 19% and 15% in the baseline and follow-up phases, respectively. The risk of reporting DS use at follow-up was similar among those reporting and not reporting AEs at baseline for most DS categories including prohormones, proteins/amino acids, individual vitamins and minerals, multivitamin/multiminerals, herbals, fish oils, joint health products, and other DSs. An exception was combination products where those reporting AEs at baseline had an increased risk of use at follow-up (risk ratio = 1.13, 95% confidence interval = 1.06-1.09). Those reporting AEs at baseline and continuing DS use in the follow-up were more likely to report AEs at follow-up compared to those not reporting baseline AEs. In conclusion, AEs reported at baseline did not deter many participants from using DSs in the follow-up period, and many SMs reporting AEs at baseline continued reporting them at follow-up.

Prevalence and adverse effects of sport-related nutritional supplements (sport drinks, bars, and gels) in the military before and during the COVID-19 pandemic: the US Military Dietary Supplement Use Study.

BACKGROUND: Sport-related nutritional supplements (SRNS) include sport drinks, sport bars, and sport gels. This investigation examined temporal patterns in SRNS use and adverse effects (AEs) reported by a single cohort of United States active-duty service members (SMs) surveyed before and during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: A stratified random sample (n = 22,858) of SMs (Air Force, Army, Navy, and Marine Corps) who completed a questionnaire on their SRNS use and AE experiences and were still on active duty were asked to complete the identical questionnaire on a second occasion. Twenty-five percent of successfully contacted SMs completed both questionnaires (n = 5,778) and were included in this investigation. The average ± standard deviation time between questionnaires was 1.3 ± 0.2 years. RESULTS: Prevalence of reported SRNS use ≥1 time/week in the baseline (BL) and follow-up (FU) phases were as follows: any SRNS: BL = 46%, FU = 41%; sport drinks: BL = 31%, FU = 28%; sport bars: BL = 30%, FU = 24%; sport gels: BL = 4%, FU = 4%. Reported weekly aerobic and resistance training durations were reduced in the FU period (8% and 26%, respectively). The proportion of SMs reporting SRNS use in both study phases was as follows: any SRNS = 62%, sport drinks = 54%, sport bars = 50%, sport gels = 35%. Prevalence of reported AEs in the BL and FU phases were as follows: any SRNS: BL = 1.9%, FU = 1.9%; sport drinks: BL = 1.0%, FU = 1.3%; sport bars: BL = 1.7%, FU = 1.4%; sport gels: BL = 3.3%, FU = 2.5%. The proportion of SMs reporting AEs in both phases was as follows: any SRNS = 14%, sport drinks = 11%, sport bars = 17%, sport gels = 0%. CONCLUSIONS: Overall SRNS use prevalence decreased slightly in the FU period, possibly because of reduced physical training related to military restrictions imposed during the emergence of COVID-19 between surveys. A large proportion of SMs reported changing their use patterns in the FU with some discontinuing use and others initiating use. The AE incidence was similarly low in the BL and FU phases, and few SMs reported AEs in both phases suggesting AEs were transitory. AE reporting for SRNSs was much lower than previously found for dietary supplements, possibly because of greater government regulatory control over SRNSs.

Associations between clinically diagnosed medical conditions and dietary supplement use: the US military dietary supplement use study.

OBJECTIVE: This study examined associations between multiple dietary supplement (DS) categories and medical conditions diagnosed by health professionals. DESIGN: Cross-sectional. SETTING: Volunteers completed an online questionnaire on DS use and demographic/lifestyle factors. Medical diagnoses were obtained from a comprehensive military electronic medical surveillance system and grouped into twenty-four clinically diagnosed medical conditions (CDMC). PARTICIPANTS: A stratified random sample of US service members (SM) from all military services (n 26 680). RESULTS: After adjustment for demographic/lifestyle factors (logistic regression), higher risk was found for 92 % (22/24) of CDMC among individual vitamins/minerals users, 58 % (14/24) of CDMC among herbal users, 50 % (12/24) of CDMC among any DS users and 46 % (11/24) of CDMC among multivitamins/multiminerals (MVM) users. Among protein/amino acid (AA) users, risk was lower in 25 % (6/24) of CDMC. For combination products, risk was higher in 13 % (3/24) of CDMC and lower in 8 % (2/24). The greater the number of CDMC, the higher the prevalence of DS use in most DS categories except proteins/AA where prevalence decreased. CONCLUSIONS: Users in many DS categories had a greater number of CDMC, but protein/AA users had fewer CDMC; results for combination products were mixed. These data indicate those with certain CDMC were also users in some DS categories, especially individual vitamins/minerals, herbals and MVM. Data are consistent with the perception that use of DS enhances health, especially in those with CDMC. Protein/AA and combination product users were more likely to be younger, more physically active men, factors that likely reduced CDMC.

Dietary Supplement and Prescription Medication Use Among US Military Service Members With Clinically Diagnosed Medical Conditions: The US Military Dietary Supplement Use Study.

BACKGROUND: Use of prescription medications (PMs) with dietary supplements (DSs) can be hazardous because of potential adverse interactions, but patterns of dual use in military service members (SMs) has not been examined. OBJECTIVE: Investigate dual use of filled PMs (FPMs) and DSs, factors associated with dual use, and dual use among SMs with clinically diagnosed medical conditions (CDMCs). DESIGN: Cross-sectional. Data on FPMs and CDMCs were obtained from medical surveillance records. Between December 2018 and August 2019, participants completed a questionnaire on DS use in the previous 6 months. PARTICIPANTS: A stratified random sample of 26,880 SMs from all military services. MAIN OUTCOME MEASURES: Prevalence of dual use of FPMs with DSs within a 6-month period, demographic/lifestyle factors associated with dual use, and prevalence of dual use among SMs with CDMCs. STATISTICAL ANALYSIS: Prevalences were calculated as percents, χ2 statistics examined differences across various strata of demographic and lifestyle characteristics, and univariable and multivariable logistic regression determined the odds of using FPMs with DSs for various CDMCs. RESULTS: About one-half (49%) of SMs had dual use of FPMs with DSs in the 6-month period. Dual use was higher among women; increased with older age, more formal education, higher body mass index, and more physical activity; was highest among American Indian SMs and lowest among Asian SMs; was higher among former tobacco users; and was highest among Army personnel and lowest among Marine Corps personnel. The overall prevalence of dual use in the 6-month period was higher among those with a CDMC than those without (62% vs 19%), and this relationship was maintained for 20 International Classification of Diseases, Revision 10, code groupings covering virtually all CDMCs. CONCLUSION: This is the first study to document a high prevalence of dual FPMs and DSs in SMs, especially among those with CDMCs.

Prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among active duty United States military personnel.

BACKGROUND: Although representative data on caffeine intake in Americans are available, these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among United States active duty military service members (SMs). METHODS: A stratified random sample of SMs were asked to complete an on-line questionnaire on their personal characteristics and consumption of caffeinated products (exclusive of dietary supplements). Eighteen percent (n = 26,680) of successfully contacted SMs (n = 146,365) completed the questionnaire. RESULTS: Overall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218 ± 2 and 167 ± 3 mg/day for men and women, respectively. Caffeine consumers ingested 243 ± 2 mg/day (251 ± 2 mg/day men, 195 ± 3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p = 0.12). Among individual caffeinated products, coffee had the highest use (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with caffeine use (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank. CONCLUSION: Compared to National Health and Nutrition Examination Survey data, daily caffeine consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.

Adverse Effects Associated with Multiple Categories of Dietary Supplements: The Military Dietary Supplement Use Study.

BACKGROUND: About 50% of Americans and 70% of US military service members (SMs) regularly use dietary supplements (DSs) and some are associated with adverse effects (AEs). SMs are more likely to use unsafe DSs than civilians. OBJECTIVE: The aim of this investigation was to examine the prevalence of, and factors associated with, AEs. DESIGN: Cross-sectional. PARTICIPANTS: A stratified random sample of 200,000 US SMs from the Air Force, Army, Marine Corps, and Navy were obtained from military workforce records. Eighteen percent (n = 26,681) of successfully contacted SMs (n = 146,365) volunteered to participate between December 2018 and August 2019. Participants completed a detailed online questionnaire on demographic characteristics, lifestyle factors, and AEs associated with DS use. MAIN OUTCOME MEASURE: Prevalence of, and factors associated with, AEs among DS users. STATISTICAL ANALYSIS: Prevalence of AEs was calculated by DS categories. Linear trends, χ2 statistics, and multivariable logistic regression examined associations between AEs and demographic characteristics, lifestyle factors, and number DSs consumed. RESULTS: Proportion of DS users (≥ 1 time /week) reporting ≥1 AE was 18% overall, 20% for combination products (ie, weight loss, muscle building, and before/after workout supplements), 8% for purported prohormones, 6% for protein/amino acid products, 6% for multivitamin/multiminerals, 6% for individual vitamins/minerals, 4% for herbal products, and 2% for joint health products. Combination products are very popular in military personnel with nearly half of SMs regularly taking them. In multivariable analysis, reporting AEs were independently associated with female gender, younger age, higher body mass index, smoking, higher alcohol intake, service in the Army, Navy, or Marine Corps (compared with Air Force), and consumption of a greater number of DSs. CONCLUSIONS: A large proportion of SMs report experiencing AEs, especially users of combination products and purported prohormone supplements. This study presents contemporary data collected from a very large at-risk population on potentially hazardous categories of DSs.

Adverse effects associated with use of specific dietary supplements: The US Military Dietary Supplement Use Study.

Dietary supplements (DSs) are used by 50% of Americans and 70% of United States military service members (SMs); some have adverse effects (AEs). This cross-sectional investigation examined AEs associated with specific DSs. A stratified random sample of SMs from the Air Force, Army, Marine Corps, and Navy was obtained. Volunteers completed a questionnaire reporting AEs for 96 generic and 62 specific DSs. The highest prevalence (≥1 AE) in specific DS categories was 35% prohormones, 33% weight loss supplements, 26% pre/post workout supplements, 14% herbal products, 12% multivitamin/multiminerals, 11% protein/amino acids, 9% muscle building supplements, 7% other DSs, 6% joint health products, and 5% individual vitamins/minerals. Specific DSs of concern (with proportion reporting AEs) included: Libido Max® (35%), Hydroxycut Hardcore® (33%), OxyElite® (33%), Roxylean® (31%), Growth Factor 9® (30%), Super HD® (29%), Hydroxycut Advanced® (29%), Lipo 6® (28%), The Ripper® (27%), Test Booster® (27%), Xenadrine Xtreme Thermogenic® (27%), C4 Extreme® (26%), and C4 Original® (25%). Products marketed for weight loss, use before/after workout, and prohormones had the highest AE prevalence. DSs can contain substances with independent/additive AEs and/or interact with other ingredients or prescribed medications. Methods described here could provide a continuous surveillance system detecting dangerous DSs entering the market.

Anthropometrics and Body Composition Predict Physical Performance and Selection to Attend Special Forces Training in United States Army Soldiers.

INTRODUCTION: Anthropometrics and body composition characteristics differentiate many types of athletes and are related to performance on fitness tests and tasks in military personnel. Soldiers competing to enter elite units must demonstrate physical fitness and operational competence across multiple events. Therefore, this study determined whether anthropometrics and body composition predicted physical performance and selection for special forces training among soldiers attending the rigorous Special Forces Assessment and Selection (SFAS) course. MATERIALS AND METHODS: Soldiers attending the SFAS course between May 2015 and March 2017 were enrolled in a longitudinal, observational study. Anthropometrics (height, body mass, and body mass index [BMI]; n = 795) and body composition measured by dual-energy X-ray absorptiometry (percentage body fat, fat mass, lean mass, bone mineral content [BMC], and bone mineral density [BMD]; n = 117) were assessed before the course start. Associations with physical performance were determined with correlation coefficients. Associations with selection were determined with analyses of variance and t-tests; effect sizes were calculated as Cohen's d. The U.S. Army Research Institute of Environmental Medicine Institutional Review Board (IRB) initially approved this study, and the U.S. Army Medical Research and Development Command IRB approved the continuing review. RESULTS: Lower percentage body fat and fat mass predicted better performance on all assessments: Army Physical Fitness Test (APFT), pull-ups, SFAS run, loaded road march, obstacle course, and land navigation (P ≤ .05). Higher lean mass predicted better performance on the loaded road march (P ≤ .05). Lower body mass and BMI predicted better performance on APFT, pull-ups, run, and obstacle course; higher body mass and BMI predicted better performance on the loaded road march (P ≤ .05). Shorter stature predicted better performance on push-ups (APFT) and pull-ups; taller stature predicted better performance on SFAS run and loaded road march (P ≤ .05). On average, the selected soldiers were taller (179.0 ± 6.6 vs. 176.7 ± 6.7 cm), had higher body mass (85.8 ± 8.8 vs. 82.1 ± 9.6 kg), BMI (26.8 ± 2.2 vs. 26.3 ± 2.6 kg/m2), lean mass (67.2 ± 7.3 vs. 61.9 ± 7.6 kg), BMC (3.47 ± 0.40 vs. 3.29 ± 0.56 kg), and BMD (1.34 ± 0.10 vs. 1.28 ± 0.10 g/cm2), and lower percentage body fat (17.3 ± 3.4 vs. 20.1 ± 4.5%) and fat mass (14.2 ± 3.7 vs. 15.8 ± 4.4 kg) (P ≤ .05). Effect sizes were largest for lean mass (Cohen's d = 0.71) and percentage body fat (d = 0.70), followed by BMD (d = 0.60), body mass (d = 0.40), fat mass (d = 0.39), BMC (d = 0.37), height (d = 0.35), and BMI (d = 0.21). Body mass adjustment attenuated associations between height and selection. CONCLUSIONS: Anthropometrics and body composition are predictors of physical performance and SFAS success. Since these measures are modifiable (excluding height), they may be the focus of intervention studies aiming to improve performance in arduous military training courses, sports that require competition in multiple events, and occupations that have varied physical demands, such as firefighting, law enforcement, and construction.

Prevalence, factors associated with use, and adverse effects of sport-related nutritional supplements (sport drinks, sport bars, sport gels): the US military dietary supplement use study.

BACKGROUND: Sport-related nutritional supplements (SRNSs) include sport drinks, sport bars, and sport gels. Previous studies indicate that 25-35 % of athletes and 25-50 % of military personnel report using these supplements. This study examined prevalence, factors associated with use, and adverse effects (AEs) of SRNSs among United States military service members (SMs). METHODS: A stratified random sample of 200,000 SMs was obtained from military workforce records, and asked to complete a survey on demographics, SRNS use, and AEs experienced. About 18 % (n = 26,681) of contacted SMs (n = 146,365) completed the survey between December 2018 and August 2019. RESULTS: Overall, 45 % of SMs used ≥ 1 SRNS at least once per week in the past 6 months. Prevalence of use (± standard error) for sport drinks, bars, and gels were 32 ± 0.3, 27 ± 0.3, and 3 ± 0.1 %, respectively. Use of 1, 2, or 3 SRNSs was 28.9 ± 0.5, 13.6 ± 0.6, and 2.2 ± 0.6 %, respectively. Multivariable logistic regression indicated greater use of any SRNS was independently associated with male gender, younger age, single marital status, more weekly aerobic or resistance training, tobacco use, higher alcohol intake, officer status, combat arms occupations, and service in the Marine Corps or Navy (compared to the Air Force). Overall, the proportion of users reporting ≥ 1 AE was 2.0 ± 0.1 %, with 1.3 ± 0.1 % for sport drinks, 1.6 ± 0.2 % for sport bars, and 2.8 ± 0.6 % for sport gels. CONCLUSIONS: This large study of a stratified random sample of SMs found that nearly half of SMs consumed SRNSs weekly, and self-reported AEs were comparatively low. The AE incidence for SRNSs was much lower than typically found for dietary supplements, possibly because of more rigorous regulatory oversight for SRNSs.

Prevalence of and Factors Associated with Dietary Supplement Use in a Stratified, Random Sample of US Military Personnel: The US Military Dietary Supplement Use Study.

BACKGROUND: About 50% of Americans and 70% of US military service members use dietary supplements (DSs). OBJECTIVES: This cross-sectional survey examined current prevalence of and factors associated with DS use in service members. METHODS: A stratified random sample of 200,000 service members from the Air Force, Army, Marine Corps, and Navy was obtained from military manpower records, and these service members were asked to complete a questionnaire on their DS use and personal characteristics. Chi-square statistics and multivariable logistic regression examined differences across various strata of demographic, lifestyle, and military characteristics. RESULTS: About 18% of successfully contacted service members (n = 26,681) completed the questionnaire between December 2018 and August 2019 (mean ± SD age: 33 ± 8 y, 86% male). Overall, 74% reported using ≥1 DS/wk. Multivitamins/multiminerals were the most commonly used DSs (45%), followed by combination products (44%), proteins/amino acids (42%), individual vitamins/minerals (31%), herbals (20%), joint health products (9%), and purported prohormones (5%). In multivariable analysis, factors independently associated with DS use included female gender [OR (female/male): 1.91; 95% CI: 1.73, 2.11], older age [OR (≥40/18-24 y): 1.25; 95% CI: 1.08, 1.44], higher education level [OR (college degree/high school or less): 1.35; 95% CI: 1.19, 1.53], higher BMI [OR (≥30/<25 kg/m2): 1.37; 95% CI: 1.25, 1.52], more weekly resistance training [OR (>300/≤45 min/wk): 5.05; 95% CI: 4.55, 5.61], smokeless tobacco use [OR (user/nonuser): 1.30; 95% CI: 1.17, 1.44], higher alcohol intake [OR (≥72/0 mL/wk): 1.41; 95% CI: 1.29, 1.54], and higher military rank [OR (senior officer/junior enlisted): 1.26; 95% CI: 1.06, 1.51]. CONCLUSIONS: Compared with civilian data from the NHANES, service members were much more likely to use DSs and used different types of DSs, especially combination products and proteins/amino acids often used to purportedly enhance physical performance. Comparisons with previous military data suggest DS use has increased over time.

Vitamin A and Bone Fractures.

Vitamin A is a generic term describing compounds that have the same biological activity as retinol. Dietary vitamin A can be obtained from "provitamin A" carotenoids (e.g., ß-carotene) found in plant foods such as carrots, cantaloupes, and sweet peppers, or as "preformed vitamin A" found in many dietary supplements, animal livers, and vitamin A-fortified foods, such as breakfast cereals, milk, cheese, and yogurt. Low consumption of vitamin A can cause night blindness, reduce immune function, and have detrimental developmental effects. Several lines of evidence suggest that excessive dietary intake of vitamin A might be associated with an increased risk of bone fractures. Meta-analysis of observational human studies that have examined vitamin A and fractures suggests that dietary consumption of large amounts of vitamin A in the form of ß-carotene likely has a protective effect, reducing the risk of fractures. On the other hand, meta-analyses that have specifically examined hip fractures have shown that total vitamin A (all types) or retinol consumption may increase the risk of hip fractures. Until more information is available, it is advisable to consume vitamin A primarily from plant sources, avoid excessive consumption from dietary supplements and animal sources, and lower consumption from fortified foods.

Exertional Heat Stroke: Pathophysiology, Epidemiology, Diagnosis, Treatment, and Prevention.

Temperature increases due to climate changes and operations expected to be conducted in hot environments make heat-related injuries a major medical concern for the military. The most serious of heat-related injuries is exertional heat stroke (EHS). EHS generally occurs when health individual perform physical activity in hot environments and the balance between body heat production and heat dissipation is upset resulting in excessive body heat storage. Blood flow to the skin is increased to assist in dissipating heat while gut blood flow is considerably reduced, and this increases the permeability of the gastrointestinal mucosa. Toxic materials from gut bacteria leak through the gastrointestinal mucosa into the central circulation triggering an inflammatory response, disseminated intravascular coagulation (DIC), multiorgan failure, and vascular collapse. In addition, high heat directly damages cellular proteins resulting in cellular death. In the United States military, the overall incidence of clinically diagnosed heat stroke from 1998 to 2017 was (mean ± standard deviation) 2.7 ± 0.5 cases/10,000 Soldier-years and outpatient rates rose over this period. The cornerstone of EHS diagnosis is recognition of central nervous dysfunction (ataxia, loss of balance, convulsions, irrational behavior, unusual behavior, inappropriate comments, collapse, and loss of consciousness) and a body core temperature (obtained with a rectal thermometer) usually >40.5°C (105°F). The gold standard treatment is whole body cold water immersion. In the field where water immersion is not available it may be necessary to use ice packs or very cold, wet towels placed over as much of the body as possible before transportation of the victim to higher levels of medical care. The key to prevention of EHS and other heat-related injuries is proper heat acclimation, understanding work/rest cycles, proper hydration during activity, and assuring that physical activity is matched to the Soldiers' fitness levels. Also, certain dietary supplements (DSs) may have effects on energy expenditure, gastrointestinal function, and thermoregulation that should be considered and understood. In many cases over-motivation is a major risk factor. Commanders and trainers should be alert to any change in the Soldier's behavior. Proper attention to these factors should considerably reduce the incidence of EHS.

Effects of Oral Chondroitin Sulfate on Osteoarthritis-Related Pain and Joint Structural Changes: Systematic Review and Meta-Analysis.

Osteoarthritis (OA) is a disorder involving the deterioration of articular cartilage and underlying bone and is associated with symptoms of pain and disability. In military personnel, the incidence of OA has increased between 2000 and 2012 and was the first or second leading cause of medical separations in this period. It has been suggested that consumption of chondroitin sulfate (CS) may reduce the pain and joint deterioration associated with OA. This article reports on a systematic review and meta-analysis of the effectiveness of CS on reducing OA-related pain and joint deterioration. PubMed and Ovid Embase databases and other sources were searched to find randomized, double-blind, placebo-controlled trials on the effects of orally consumed CS on pain and/or joint structure. The outcome measure was the standardized mean difference (SMD) which was the improvement in the placebo groups minus the improvement in the CS groups divided by the pooled standard deviation. There were 18 trials meeting the review criteria for pain with SMD -0.41, 95% confidence interval (95% CI) -0.57 to -0.25 (negative SMD favors CS). Six studies met the review criteria for joint space narrowing with SMD -0.30, 95% CI -0.61 to +0.00. Two studies meet the review criteria for cartilage volume with SMD -0.11, 95% CI -0.48 to +0.26. Larger dosages (1200mg/d) had greater pain reduction efficacy than lower dosages (≤ 1000mg/d). These data suggest that CS has small to moderate effectiveness in reducing OA-related pain but minimal effects on joint space narrowing and no effect on cartilage volume. It is important that clinicians recommend pharmaceutical-grade CS to their patients due to the variability in the amount of CS in dietary supplements purporting to contain CS.

Effects of Oral Glucosamine Sulfate on Osteoarthritis-Related Pain and Joint-Space Changes: Systematic Review and Meta-Analysis.

BACKGROUND: Osteoarthritis (OA) is a disorder involving deterioration of articular cartilage and underlying bone and is associated with symptoms of pain and disability. Glucosamine is a component of articular cartilage naturally synthesized in the body from glucose and incorporated into substances contained in the cartilage. It has been suggested that consumption of glucosamine may reduce the pain of OA and may have favorable effects on structural changes in the cartilage. This article presents a systematic review and meta-analysis of the effectiveness of orally consumed glucosamine sulfate (GS) on OA-related pain and joint structural changes. METHODS: PubMed and Ovid Embase were searched using specific search terms to find randomized, double-blinded, placebo-controlled trials on the effects of GS on pain and/or joint-space narrowing. The outcome measure was the standardized mean difference (SMD), which was the improvement in the placebo groups minus the improvement in the GS groups divided by the pooled standard deviation. RESULTS: There were 17 studies meeting the review criteria for pain, and the summary SMD was -0.35, with a 95% confidence interval (95% CI) = -0.54 to -0.16 (negative SMD is in favor of GS). Of the 17 studies, 7 showed a statistically significant reduction in pain from GS use. Four studies met the review criteria for joint space narrowing with a summary SMD = -0.10 (95% CI = -0.23 to +0.04). Studies without involvement of the commercial glucosamine industry had a lower (but still significant) pain reduction efficacy (summary SMD = -0.19, 95% CI = -0.39 to -0.02) than those with industry involvement. Several smaller dosages throughout the day had larger pain reduction effects than a single daily large dose (1500 mg). CONCLUSION: These data indicate that GS may have a small to moderate effect in reducing OA-related pain but little effect on joint-space narrowing. Until there is more definitive evidence, healthcare providers should be cautious in recommending use of GS to their patients. Because GS dosages used in studies to date resulted in mild and transient adverse effects, and these were similar to that experienced by patients receiving placebos, larger GS doses possibly could be investigated in future studies.

Dietary Supplement Use in a Large, Representative Sample of the US Armed Forces.

BACKGROUND: Dietary supplement (DS) use is prevalent among the US Armed Forces personnel, but representative cross-service comparisons and characteristics of personnel using DSs are limited. OBJECTIVE: Examine DS use and characteristics associated with use in a representative sample of US Armed Forces personnel (Army, Navy, Air Force, Marine Corps, and Coast Guard) using data from the 2011 Department of Defense Survey of Health-Related Behaviors. DESIGN AND PARTICIPANTS: A stratified random sample of service members (SMs) was contacted and asked to complete a questionnaire assessing personal characteristics and DS use. RESULTS: Overall, 69% of the 39,877 SMs reported using DSs ≥1 time per week. The most commonly used DSs were multivitamin or multiminerals (50%), antioxidants (34%), individual vitamins or minerals (33%), bodybuilding supplements (27%), fish oils (26%), herbals (16%), and weight-loss supplements (16%). Multiple logistic regression indicated overall DS use was higher among women, those with higher educational levels, Marine Corps SMs, officers, those with higher body mass index, those engaged in greater physical activity and weight training, and people in weight control programs. DS use was lower when peer groups or leadership discouraged substance abuse. CONCLUSIONS: DS use was considerably higher in the US Armed Forces compared with civilian populations, although many demographic and lifestyle factors associated with use were similar. Some categories of DSs extensively used by SMs such as bodybuilding supplements have been associated with adverse events. Discouraging substance abuse through peer groups and leadership actions may reduce use of unnecessary or dangerous DSs.

Stress Fractures: Etiology, Epidemiology, Diagnosis, Treatment, and Prevention.

Stress fractures are part of a continuum of changes in healthy bones in response to repeated mechanical deformation from physical activity. If the activity produces excessive repetitive stress, osteoclastic processes in the bone may proceed at a faster pace than osteoblastic processes, thus weakening the bone and augmenting susceptibility to stress fractures. Overall stress fracture incidence is about three cases per 1,000 in active duty Servicemembers, but it is much higher among Army basic trainees: 19 per 1,000 for men and 80 per 1,000 for women. Well-documented risk factors include female sex, white ethnicity, older age, taller stature, lower aerobic fitness, prior physical inactivity, greater amounts of current physical training, thinner bones, cigarette smoking, and inadequate intake of vitamin D and/or calcium. Individuals with stress fractures present with focal tenderness and local pain that is aggravated by physical activity and reduced by rest. A sudden increase in the volume of physical activity along with other risk factors is often reported. Simple clinical tests can assist in diagnosis, but more definitive imaging tests will eventually need to be conducted if a stress fracture is suspected. Plain radiographs are recommended as the initial imaging test, but magnetic resonance imaging has higher sensitivity and is more likely to detect the injury sooner. Treatment involves first determining if the stress fracture is of higher or lower risk; these are distinguished by anatomical location and whether the bone is loaded in tension (high risk) or compression (lower risk). Lowerrisk stress fractures can be initially treated by reducing loading on the injured bone through a reduction in activity or by substituting other activities. Higher-risk stress fractures should be referred to an orthopedist. Investigated prevention strategies include modifications to physical training programs, use of shock absorbing insoles, vitamin D and calcium supplementation, modifications of military equipment, and leadership education with injury surveillance.

Caffeine consumption among active duty United States Air Force personnel.

Data from the National Health and Nutrition Examination Survey (NHANES) indicated that 89% of Americans regularly consumed caffeinated products, but these data did not include military personnel. This cross-sectional study examined caffeine consumption prevalence, amount of daily consumption, and factors associated with caffeine intake in active duty United States (US) Air Force personnel. Service members (N = 1787) stationed in the US and overseas completed a detailed questionnaire describing their intake of caffeine-containing products in addition to their demographic, lifestyle, and military characteristics. Overall, 84% reported consuming caffeinated products ≥1 time/week with caffeine consumers ingesting a mean ± standard error of 212 ± 9 mg/day (224 ± 11 mg/day for men, 180 ± 12 mg/day for women). The most commonly consumed caffeinated products (% users) were sodas (56%), coffee (45%), teas (36%), and energy drinks (27%). Multivariate logistic regression modeling indicated that characteristics independently associated with caffeine consumption (≥1 time/week) included older age, ethnicity other than black, tobacco use, less aerobic training, and less sleep; energy drink use was associated with male gender, younger age, tobacco use, and less sleep. Compared to NHANES data, the prevalence of caffeine consumption in Air Force personnel was similar but daily consumption (mg/day) was higher.

Load Carriage-Related Paresthesias (Part 2): Meralgia Paresthetica.

This is the second of a two-part series addressing symptoms, evaluation, and treatment of load carriage- related paresthesias. Part 1 addressed rucksack palsy and digitalgia paresthetica; here, meralgia paresthetica (MP) is discussed. MP is a mononeuropathy involving the lateral femoral cutaneous nerve (LFCN). MP has been reported in load carriage situations where the LFCN was compressed by rucksack hipbelts, pistol belts, parachute harnesses, and body armor. In the US military, the rate of MP is 6.2 cases/10,000 personyears. Military Servicewomen have higher rates than Servicemen, and rates increase with age, longer loadcarriage distance or duration, and higher body mass index. Patients typically present with pain, itching, and paresthesia on the anterolateral aspect of the thigh. There are no motor impairments or muscle weakness, because the LFCN is entirely sensory. Symptoms may be present on standing and/or walking, and may be relieved by adopting other postures. Clinical tests to evaluate MP include the pelvic compression test, the femoral nerve neurodynamic test, and nerve blocks using lidocaine or procaine. In cases where these clinical tests do not confirm the diagnosis, specialized tests might be considered, including somatosensory evoked potentials, sensory nerve conduction studies, high-resolution ultrasound, and magnetic resonance imaging. Treatment should initially be conservative. Options include identifying and removing the compression if it is external, nonsteroidal inflammatory medication, manual therapy, and/or topical treatment with capsaicin cream. Treatments for intractable cases include injection of corticosteroids or local anesthetics, pulsed radiofrequency, electroacupuncture, and surgery. Military medical care providers may see cases of MP, especially if they are involved with units that perform regular operations involving load carriage.

Demographic factors associated with dietary supplement prescriptions filled by United States Military Service Members 2005-2013.

BACKGROUND: Dietary supplements (DSs) can be purchased over-the-counter but may also be prescribed by medical personnel for specific therapeutic reasons. Few studies have examined this latter source of DSs despite the fact that 79% of physicians and 82% of nurses have recommended DSs to their patients. This investigation examined demographic factors associated with temporal trends in oral DS prescriptions filled by all United States (US) service members (SMs) from 2005 to 2013 (n = 1,427,080 ± 22,139, mean ± standard deviation per year). METHODS: The Food and Drug Administration National Drug Code database and the formularies of the US Defense Health Agency's Pharmacoeconomic Center were queried to identify DSs available to SMs. The number of these DS prescriptions filled by all SMs from 2005 through 2013 was then obtained from the US Department of Defense Pharmacy Data Transaction System. Data were grouped by American Hospital Formulary System (AHFS) pharmacologic-therapeutic classifications and examined over time. Denominators (number of SMs each year) were obtained from the Defense Health Agency. RESULTS: Major findings included 1) generally greater prevalence of prescriptions filled by women and older SMs for most AHFS categories; 2) a temporal decline in total prescriptions filled by Marine Corps personnel accounted for by a decline in the prevalence of zinc preparations filled by younger male Marines; 3) a temporal decline in the prevalence of iron preparations filled by women; 4) a temporal increase in the prevalence of prescriptions for replacement preparations filled by women accounted for largely by more prescriptions for calcium compounds; and 5) a temporal decline in the prevalence of prescriptions filled for cathartics/laxatives in older SMs accounted for largely by a decline in prescriptions for sodium/potassium compounds. CONCLUSIONS: These temporal trends may be associated with the greater health care utilization of women and older SMs as well as the perceptions of prescribers and/or patients on appropriate roles of these substances in medicine and public health.

Temporal trends in dietary supplement prescriptions of United States military service members suggest a decrease in pyridoxine and increase in vitamin D supplements from 2005 to 2013.

Dietary supplements (DSs) can be obtained over-the-counter but can also be prescribed by health-care providers for therapeutic reasons. Few studies have documented this later source despite the fact that 79% of physicians and 82% of nurses have recommended DSs to patients. This investigation assessed prevalence and temporal trends in oral DS prescriptions filled by all United States service members (SMs) from 2005 to 2013 (n = 1 427 080 ± 22 139, mean ± standard deviation (SD)/y). We hypothesize that there would be temporal variations in specific types of DSs. Data obtained from Department of Defense Pharmacy Data Transaction System were grouped by American Hospital Formulary System pharmacologic-therapeutic classifications and prevalence examined over time. About 11% of SMs filled one or more DS prescriptions of 235 180 ± 4926 (mean ± SD) prescriptions/y over the 9-year period. Curve-fitting techniques indicated significant linear declines over time for multivitamins (P = .004), iron preparations (P < .001), antacids (P < .001), and vitamin B and B complex vitamins (P < .001). There were significant quadratic trends indicating a rise in early years followed by a leveling off in later years for replacement preparations (P < .001) and vitamin C (P < .001). There were significant quadratic trends (P < .001) for vitamin E indicating a decline in early years and leveling off in later years, and vitamin D indicating little change in early years followed by a large rise subsequently (P < .001). This study identified temporal trends in specific DS categories that may be associated with changing perceptions of prescribers and/or patients of the appropriate roles of DSs in medicine and public health.