Body fat assessment in women. Special considerations

Methods of in vivo body fat estimation are based on simple assumptions about body composition which work reasonably well for men, while estimations in women have been largely extrapolated from the male studies so that women are treated as men with just more of the same fat. Compared to men, fat regulation in women is considerably more elaborate, with more and different sites for storage and a larger proportion of fat distributed to the extremities and in subcutaneous locations. Thus, a ratio of waist-to-hips girth which reflects increasing fatness in men only specifies 2 different extremes of a broader spectrum of possibilities for fat distribution in women. This complicates anthropometric prediction of total fatness and clearly limits the generalisability of any female equations. Anthropometric methods are further confounded by difficulties in the criterion methods against which they are developed. For example, the validity of assumptions about the fractional contributions of bone mineral and body water to fat-free mass and density may not hold through the reproductive cycles. Women athletes involved in weight-bearing or strength training may increase bone mineral content above average values but if they become amenorrhoeic, bone mineral density may fall significantly below average values. Fit premenopausal women distribute fat differently and have a higher bone mineral content than unfit postmenopausal women. Genetic factors which also affect criterion method assumptions in men are superimposed on these additional complications in women. Body fat in female athletes extends across almost the entire range of female fatness, with some of the lowest measurements in distance runners and body builders which fall into the normal male range, but also with some relatively high values in swimmers and strength athletes, which would classify these women as obese by male standards. Thus, total body fat reflects a more complex regulation and has a different meaning to health and performance in women than it does for men. Predictive equations for women athletes should be developed with a view to the specific group and ultimate purpose to which they will be applied.

Comparison of the effects of high dose testosterone and 19-nortestosterone to a replacement dose of testosterone on strength and body composition in normal men

We examined the extent to which supraphysiological doses of androgen can modify body composition and strength in normally virilized men. In doubly blind tests, 30 healthy young men received testosterone enanthate (TE) or 19-nortestosterone decanoate (ND), at 100 mg/wk or 300 mg/wk for 6 weeks. The TE-100 mg/wk group served as replacement dose comparison, maintaining pretreatment serum testosterone levels, while keeping all subjects blinded to treatment, particularly through reduction in testicular volumes. Isokinetic strength measurements were made for the biceps brachii and quadriceps femoris muscle groups before treatment and 2-3 days after the 6th injection. Small improvements were noted in all groups but the changes were highly variable; a trend to greater and more consistent strength gain occurred in the TE-300 mg/wk group. There was no change in weight for TE-100 mg/wk but an average gain of 3 kg in each of the other groups. No changes in 4 skinfold thicknesses or in estimated percent body fat were observed. Of 15 circumferences, significant increases were observed only for men receiving TE-300 mg/wk (shoulders) and ND-300 mg/wk (shoulders and chest). The data suggest that high dose androgens increase body mass and may increase strength in normal men but, except for a consistent weight gain with greater than replacement doses, the detectable changes were highly variable and relatively small, especially in comparison to the significant alterations which were observed for other markers of androgen action.

Serum lipids and lipoproteins in continuous or cyclic medroxyprogesterone acetate treatment in postmenopausal women treated with conjugated estrogens

This study evaluates effects on serum lipids of continuous or sequential progestogens for hormonal replacement in women. Subjects received either a cyclic regimen of replacement (0.625 mg/d of conjugated equine estrogens (Es) for 25 days/month and 10 mg medroxyprogesterone acetate [MPA] for the last 13 days of E) or 0.625 mg/d E along with either 5 or 10 mg MPA (Provera, Upjohn Company, Kalamazoo, MI). Study parameters were measured over a 24-week period. No differences in total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, apolipoproteins I and II, sex hormone-binding globulin, or serum MPA levels were noted between the sequential and 5 mg continuous group. The 10 mg MPA group did not have an increase in HDL or decrease in low-density lipoprotein as did the other groups.

Assessment of pubertal maturity in boys, using height and grip strength

A method is described for the convenient, noninvasive assessment of pubertal maturity in boys, which is intended for use in studies of developmentally related sports injury. Ninety-eight boys were evaluated for Tanner stage, age, height, weight, body mass index, and maximum (right or left hand) and average grip strength. Height and average grip strength were selected by discriminate analysis as independent predictors of maturity. Immature boys (Tanner stages 1-3) fell below average grip strength of 25 kg and were less than 65 inches (165 cm) in height, whereas boys who exceeded both of these measurements were mature (Tanner stage 4 or 5). This method was validated in a second sample of 99 boys with 100% specificity and sensitivities of 93.5% (immature boys) and 81% (mature boys). A subset of mature boys met the height criterion but did not achieve the average grip strength criterion for maturity. We propose the use of height and grip strength as a practical, noninvasive method to classify physical maturity in boys. In addition, we speculate that the subset of boys who are tall, but weak, may be at increased risk for certain types of sports injuries.

High-density lipoprotein cholesterol is not decreased if an aromatizable androgen is administered

We examined the influence of aromatization of testosterone on serum high-density lipoprotein cholesterol (HDL-C) and postheparin plasma hepatic triglyceride lipase activity (HTLA) in men. Eighteen healthy lean nonsmokers (ages, 20 to 33) were administered androgens in a weekly total dose of 280 mg for 12 weeks in one of three groups: testosterone enanthate (TE) (280 mg/wk intramuscularly [IM]); TE (280 mg/wk IM) + testolactone (TL) (250 mg orally [PO] four times daily); or methyltestosterone (MeT) (20 mg PO twice daily). Serum testosterone achieved steady state levels by 4 weeks with greater than 40 nmol/L (TE and TE + TL) and less than 15 nmol/L (MeT) while 17b-estradiol (E2) rose to greater than 250 pmol/L (TE) or remained below 70 pmol/L (TE + TL and MeT). LH fell to less than 5 U/L (TE and TE + TL) but remained unchanged with MeT. By 4 weeks, HDL-C had decreased significantly from 1.20 +/- 0.13 to 0.77 +/- 0.13 mmol/L (MeT), from 1.18 +/- 0.15 to 0.89 +/- 0.13 mmol/L (TE TL), and demonstrated no decrease in the TE group across the time course of the study. These changes were preceded by mean increases in HTLA of 102% (MeT) and 55% (TE + TL) over baseline, and no significant change with TE. The changes in HDL-C and HTLA returned to baseline within 2 weeks of steroid cessation. There were no changes in total cholesterol, triglycerides, or insulin in any group but, in the MeT group, apo AI levels decreased and low-density lipoprotein cholesterol (LDL-C) increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Atropine absorption after intramuscular administration with 2-pralidoxime chloride by two automatic injector devices

Compared with manual intramuscular injection, automatic injector delivery substantially enhances drug absorption rate. We examined the effect of two types of automatic injector delivery of two drugs which are components of the standard antidote to anticholinesterase poisoning and which have been previously shown to have a reduced absorption rate when mixed together in a manual injection. In crossover experiments one week apart, 20 nonsmoking healthy young male humans (ages 20-30) were studied after citrated atropine (6.9 mumol/0.7 mL) and pralidoxime chloride (3.5 mmol/2.0 mL; PAMCL) were injected sequentially into a single intramuscular site by either a multichambered autoinjector or a device which delivers the drugs into two separate intramuscular sites (MARK I). Atropine absorption was assessed by the appearance of atropine in the serum and by changes in heart rate, salivary secretion, pupil diameters, and near vision accommodation. Atropine absorption was significantly greater in the first 30 min following injection with the MARK I. The results of this study suggest that: (1) the MARK I device produces a faster absorption of atropine, probably through some combination of its broader dispersal of atropine in the muscle site and its separation of atropine from the PAMCL; (2) salivary secretion may be the most convenient and sensitive marker of atropine action; and (3) the 6.9- mumol (2-mg) dose of atropine delivered by either autoinjector gives near maximal antisialogogue activity in normal male humans.

The administration of pharmacological doses of testosterone or 19-nortestosterone to normal men is not associated with increased insulin secretion or impaired glucose tolerance

Excess androgen secretion and exogenous androgen administration may decrease insulin sensitivity and impair glucose tolerance. We examined the responses to an oral glucose tolerance test in 30 normal men before and after 6 weekly injections of androgen administered in a double-blinded study design. The men were randomly assigned to 1 of 4 treatment groups: testosterone enanthate (TE), 100 or 300 mg/week, or 19-nortestosterone decanoate (ND), 100 or 300 mg/week. Serum testosterone levels, measured 2-3 days after the last dose, did not change in the men given 100 mg TE/week, increased 3-fold in those given 300 mg TE/week, and decreased in both ND groups. All four groups had comparable reductions in serum LH levels. Weight increased significantly in all except the 100 mg TE/week group, but there was no change in waist to hip ratio in any group. In spite of the demonstrated biological effects of the doses of steroid administered, androgen administration for 6 weeks did not increase fasting serum glucose or insulin concentrations. There was also no increase in peak serum insulin levels and areas under the insulin and glucose response curves after a 100-g oral glucose load. However, the mean serum insulin area under the curve decreased significantly in the men given 300 mg ND/week. In contrast to the results of studies of 17-alkylated androgens, our results demonstrate that pharmacological doses of testosterone and the administration of 19-nortestosterone for 6 weeks do not impair glucose tolerance or alter insulin secretion in normal men.

Self-Treatment of Gynecomastia in Bodybuilders Who Use Anabolic Steroids

In brief: Gynecomastia is a cruel irony for bodybuilders who use steroids in hope of perfecting their somatotype. These athletes and their advisers perpetuate locker-room theories about which drugs to use to avoid this widely acknowledged feminizing effect. This paper presents four case reports of bodybuilders whose self-administered drug programs resulted in gynecomastia. These examples illustrate treatment strategies bodybuilders have advocated for the prevention and self-treatment of gynecomastia, which include the use of tamoxifen, mesterolone, and human chorionic gonadotropin. In fact, the recommended treatment is complete cessation of drugs. By dispelling unfounded treatment methods, physicians might help to discourage these athletes from such drug use.

Estimated prevalence of anabolic steroid use among male high school seniors

The use of anabolic-androgenic steroids (AS) is perceived by the media, by segments of the sports medicine and athletic communities, and by the public to have grown to epidemic proportions. Unfortunately, the incidence and prevalence of AS use among elite, amateur, and recreational athletes is poorly documented. This study was designed to help identify AS use patterns among the male portion of the general adolescent population. The overall participation rate on a schoolwide basis was 68.7% and on an individual basis reached 50.3%. Participants in this investigation were 12th-grade male students (N = 3403) in 46 private and public high schools across the nation who completed a questionnaire that established current or previous use of AS as well as user and nonuser characteristics. Results indicate that 6.6% of 12th grade male students use or have used AS and that over two thirds of the user group initiated use when they were 16 years of age or younger. Approximately 21% of users reported that a health professional was their primary source. The evidence indicates that educational intervention strategies should begin as early as junior high school; the intervention should not be directed only toward those individuals who participate in school-based athletics.

Self-Reported Use of Anabolic-Androgenic Steroids by Elite Power Lifters

In brief: Sixty-one athletes competed in the 1987 National Championship of the US Powerlifting Federation; all were surveyed to obtain information on anabolic-androgenic steroids regarding attitudes, patterns of use, and health effects. Of the 45 who responded to the survey, 15 admitted having used steroids. In a follow-up telephone interview of 20 of the competitors, 11 reported previous steroid use. The reason given most often for using steroids was improved athletic performance; the most common side effects reported were heightened libido, acne, and increased body hair. The small number of admitted users suggests that underreporting took place; this level of use probably represents the lower bound of steroid use among power lifters.

Inhibition of sex hormone-binding globulin production in the human hepatoma (Hep G2) cell line by insulin and prolactin

Sex hormone-binding globulin (SHBG) production in humans has been thought to be stimulated by estrogens and thyroid hormone and inhibited by androgens. However, recent data indicate that SHBG production in vitro is stimulated by both androgens and estrogens. This study was designed to determine what other hormonal factors regulate SHBG production. Since hyperinsulinemia and hyperprolactinemia both occur in disease states in which low serum SHBG levels are found, the effects of insulin and PRL were compared to and/or studied in combination with estradiol (E2), T4, and testosterone (T) in a human hepatoma cell line (Hep G2). Hep G2 cells were grown to near confluence in medium including 10% fetal calf serum, and then 72-h experimental incubations were carried out which used only fetal calf serum-free medium. Compared to control incubations, both insulin (10(-8) mol/L) and PRL (10(-8) mol/L) decreased SHBG production from 65.0 +/- 0.6 (+/- SE) to 46.8 +/- 1.1 and 46.8 +/- 1.2 nmol/10(6) cells, respectively (P less than 0.01). Insulin also inhibited both E2 and T4-stimulated SHBG production. T stimulated SHBG production to the same degree as E2. Finally, both E2 and insulin significantly increased cell number, an important consideration when expressing the effect of a hormone on SHBG production in cultured cells. We conclude that insulin and PRL inhibit SHBG production and confirm that T4, T, and E2 stimulate SHBG production in vitro. These findings suggest that insulin and PRL may be important factors in the regulation of SHBG production in vivo.

Effect of eye color on heart rate response to intramuscular administration of atropine

Melanin has been previously shown to modify the mydriatic response to atropine instillation. Skin and iris pigmentation has also been shown to modify aspects of the heart rate response to injected atropine, although these observations have been generally overlooked. In this study, 20 healthy non-smoker male subjects, ages 20-30 years, were injected by two different automatic injector devices and the mydriatic and heart rate responses in the first 90 min were reported. The group included 8 brown-eyed, 4 hazel-eyed, and 8 blue-eyed subjects. Although there were differences in the rate of atropine delivery between the two injection devices, the heart rate responses were independently modified by eye color to a magnitude of difference as great as the differences between injectors. Subjects with more pigmented irides (brown-eyed) showed a more rapid rise in heart rate compared to less pigmented irides (hazel-eyed and blue-eyed subjects). Following injection by the device with a slower atropine absorption rate, these differences were particularly enhanced and an abbreviated bradycardic phase of the heart rate response was observed for the brown-eyed subjects. This observation confirms earlier reports and suggests the possibility of an interference by melanin (in the iris or elsewhere) in atropine accessibility to selected muscarinic target sites.

Soccer injuries and their relation to physical maturity

A prospective study of injuries encountered during participation in a summer soccer camp for youths aged 6 through 17 years revealed an injury incidence of 10.6 per 1000 hours for girls (107 injuries in 458 girls) and 7.3 per 1000 hours for boys (109 injuries in 681 boys). For both sexes, the incidence of injury increased at age 14 years. One certified athletic trainer (W.D.C.) assessed and documented all injuries during the course of the study. Seventy percent of injuries involved the lower extremities. Contusions represented 35.2%, strains 27.8%, sprains 19.4%, and fractures and dislocations 2% of all reported injuries. The ankle was the most frequent site of injury in both sexes. Quadriceps strain was a common injury in boys. The boys with the highest incidence of injury were tall (greater than 165 cm) and had a weak grip (less than 25 kg), suggesting that skeletally mature but muscularly weak boys may be more susceptible to injury while playing soccer with peers of the same chronological age.

Early diagnosis of spinal metastases by CT and MR studies

Fifteen patients with known metastatic or high-risk primary cancer, normal neurologic examinations, and new abnormalities on 99mTc bone scan were evaluated with spinal CT and magnetic resonance (MR) imaging. Four patients underwent CT metrizamide myelography. Spinal CT and MR agreed in 14 of 15 patients demonstrating spinal metastases in 12 patients and benign disease in two. In one patient spinal CT was normal, but MR showed altered marrow signal consistent with metastatic disease. Epidural tumor was demonstrated by CT metrizamide myelography in four cases, all correctly identified by MR. Further evaluation of spinal MR in this setting is warranted.

Elevation of plasma estradiol in healthy men during a mountaineering expedition

The following study was undertaken to study the effects of multiple stressors on the pituitary-testicular axis in men. We examined the endocrine responses of 16 healthy young men participating in a mountain training exercise. Blood was drawn at 1830 m just before ascent (t = 0 h), after an overnight rest at 3050 m (t = 24 h), and immediately after a descent from 3050 m in adverse conditions (t = 48 h). Plasma E2 increased significantly through the study periods (medians: 74, 104, 164 pmol/l at t = 0, 24, 48 h) while 17 alpha-hydroxyprogesterone progressively decreased. Testosterone and the bioactive LH to immunoreactive LH ratio decreased only at 48 h. There were no changes observed for plasma cortisol, prolactin or thyroxine. The observed rise in E2 may be due to one or more stressors associated with altitude, including hypoxia and increased solar radiation. This data suggests a role for E2 in the secondary testosterone decrease.

Clinical usefulness of an algorithm for the early diagnosis of spinal metastatic disease

We have previously reported an algorithm that invokes several imaging modalities in the early detection of metastatic and benign disease of the spine in patients with cancer (J Clin Oncol 4:576, 1986). The development of new lesions (shown by Tc99m bone scans) in cancer patients with normal neurological examinations is further evaluated with plain radiographs, spinal computed tomography (CT), and CT myelography (CT-M). Of 60 patients in the original study, 28% were diagnosed as having only benign disease and the remainder had spinal metastases. Thecal sac impingement was seen in 47% of patients with metastatic disease and disruption of the posterior vertebral cortex was noted in all patients with epidural compression. We now report the 2-year follow-up of 55 of these patients. Without treatment, the 17 patients diagnosed with benign disease have shown no evidence of local failure in the spine and median survival is greater than 27 months. Thirty-eight patients diagnosed with spinal metastases had a median survival time of 16.9 months. Radiation therapy directed by CT-M findings provided pain relief in 78% of patients with back pain and metastatic disease. No patient, including 19 with thecal sac impingement, developed clinical myelopathy. These results demonstrate the usefulness of an imaging algorithm for the early identification and distinction of spinal metastatic disease and benign disease in patients with cancer.

Intraocular lenses in aviators: a review of the U.S. Army experience

Intraocular lenses are known to be efficacious in the correction of aphakia, but their suitability and durability in Army aviators has not been previously evaluated. Eight experienced pilots (preoperative flight time average: 7,660 hours), who had intraocular lens implants following removal of cataractus lenses, were studied. All had returned to flight duty, seven as pilots, with a total of 2,700 hours postoperative flight time accumulated. All were very pleased with the surgery and with the effectiveness of their lenses. Minor problems included: halos around lights in low illumination (5/8 pilots), erythropsia (2/8), and difficulties with a fixed focal length (2/8). Two aviators reported significant visual problems: complications associated with a platinum loop iris supported intraocular lens, and discomfort and glare stemming from traumatic corneal scarring. A detailed ophthalmological examination revealed abnormalities (5/8 pilots), but none which would be directly attributed to flying. Modern intraocular lenses appear to be an acceptable means of correcting aphakia in Army aviators.

Conjunctival oxygen tension at high altitude

Transconjunctival oxygen tension (PcjO2) was studied using a hypobaric chamber and during mountaineering excursions. Measurements obtained during acute chamber exposures (15-20 min) at sea level, 1829 m (6,000 ft), 3048 m (10,000 ft), 4267 m (14,000 ft) and return to sea level were (means +/- SEM): 60.1 +/- 2.7, 49.1 +/- 1.8, 38.3 +/- 2.4, 27.4 +/- 1.5, and 61.1 +/- 2.8 mm Hg, respectively (n = 13). The ratio of PcjO2 to arterial blood oxygen tension (PaO2) did not change in a consistent manner between sea level and 4267 m; PcjO2 was 74 +/- 6.9% of PaO2. The 16 subjects participating in the mountaineering phase of the study revealed similar means at sea level and 1829 m (57.4 +/- 2.4 and 46.3 +/- 1.9 mm Hg respectively), but a smaller decrement was observed at 3048 m (43.0 +/- 1.6 mm Hg). The difference between mountain and chamber values may be accounted for by a partial acclimatization to altitude brought about by longer exposure on the mountain excursions. A comparison between PcjO2 and transcutaneous oxygen tension during the chamber study suggests that a greater precision and sensitivity is obtained with measurement of oxygen tension at the conjunctival site. PcjO2 measurement is a non-invasive reflection of PaO2 which is suitable for continuous monitoring during hypoxia studies.

Transient reduction in serum HDL-cholesterol following medroxyprogesterone acetate and testosterone cypionate administration to healthy men

Serum lipids were examined in thirty normal male volunteers who had received depo-medroxyprogesterone acetate (DMPA) and testosterone cypionate (TC) in a male contraceptive trial. Progestagens have been implicated in the changes in serum lipids observed in women using oral contraceptives and this has led to concern about cardiovascular health risks associated with the long-term use of some of these preparations. The following study was done to determine if similar effects occur in men. The men in this study were divided into three DMPA dose groups (50, 100, 200 mg/month) and received intramuscular injections for six months; all men received 250 mg/month TC. There was no significant change in serum high density lipoprotein-cholesterol (HDL-C) levels during the six months of drug administration when compared to levels in the control period. However, there was a marked decrease in HDL-C during the first three months after discontinuation of the drugs (p less than 0.02). This observed change was consistent in each of the three DMPA dose groups but no dose relationship was observed. There was no statistically significant change in serum concentrations of total cholesterol, low density lipoprotein-cholesterol, triglycerides or insulin in any period of the experiment. Serum testosterone (T), estradiol, and sex hormone binding globulin (SHBG), luteinizing hormone (LH), and follicle stimulating hormone (FSH) concentrations were all significantly depressed during the drug administration period. A progestagen dose relationship was observed only for the decrease in serum testosterone and LH concentrations. Serum T and SHBG levels were still significantly reduced at 4-6 months after cessation of the drug administration. These findings demonstrate that DMPA can cause a reduction in serum HDL-C levels. It is suggested that HDL-C concentrations fell only following DMPA withdrawal as a consequence of steroid hormone changes specific to this period.