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Biomedical subjects

B Ettinger

Publications and source records attributed to B Ettinger.

At least 55 records · Page 3Linked to original sources
PubMed1997

Potassium-magnesium citrate is an effective prophylaxis against recurrent calcium oxalate nephrolithiasis.

PURPOSE: We examined the efficacy of potassium-magnesium citrate in preventing recurrent calcium oxalate kidney calculi. MATERIALS AND METHODS: We conducted a prospective double-blind study of 64 patients who were randomly assigned to receive placebo or potassium-magnesium citrate (42 mEq. potassium, 21 mEq. magnesium, and 63 mEq. citrate) daily for up to 3 years. RESULTS. New calculi formed in 63.6% of subjects receiving placebo and in 12.9% of subjects receiving potassium-magnesium citrate. When compared with placebo, the relative risk of treatment failure for potassium-magnesium citrate was 0.16 (95% confidence interval 0.05 to 0.46). Potassium-magnesium citrate had a statistically significant effect (relative risk 0.10, 95% confidence interval 0.03 to 0.36) even after adjustment for possible confounders, including age, pretreatment calculous event rate and urinary biochemical abnormalities. CONCLUSIONS: Potassium-magnesium citrate effectively prevents recurrent calcium oxalate stones, and this treatment given for up to 3 years reduces risk of recurrence by 85%.

Adult↗
PubMed1997

Correlates of kyphosis in older women. The Fracture Intervention Trial Research Group.

OBJECTIVE: To determine the association between kyphosis (degree of forward curvature of the thoracic spine) and measures of spinal osteoporosis (height loss and vertebral fractures) and chronic back pain and disability in older women. DESIGN: A cross-sectional study. SETTING: Eleven clinical centers in the United States. PARTICIPANTS: A total of 6439 community-dwelling osteoporotic women aged 55-80 enrolled in the Fracture Intervention Trial (FIT), a multicenter clinical trial of alendronate. MEASUREMENTS: Thoracic curvature was measured at baseline using a Debreuner Kyphometer. Height loss was determined by subtracting current height measured with a Harpenden stadiometer from self-reported height at age 25. Vertebral fractures were defined by morphometry and semiquantitative reading of lateral thoracic and lumbar spine radiographs, and chronic back pain and back-related disability were assessed by questionnaire. RESULTS: After adjustment for age, a 15 degrees increase in kyphosis was associated with losing more than 4 cm of height (OR, 1.88; 95% CI, 1.79-2.03) and having a vertebral fracture (OR, 1.57; 95% CI, 1.46-1.69). Kyphosis was more strongly related to thoracic fractures than to lumbar fractures, and kyphosis was most prominent in women with multiple thoracic wedge fractures. Kyphosis was also associated with upper back pain (OR per 15 degrees increase, 1.62; 95% CI 1.47-1.79) and middle back pain (OR per 15 degrees increase, 1.24; 95% CI 1.12-1.36), but it was not related to lower back pain (OR per 15 degrees increase, 0.98; 95% CI 0.90-1.05). Women with greater degrees of kyphosis were only slightly more likely to report back-related disability (OR per 15 degrees increase, 1.18; 95% CI 1.03-1.35) and poorer health status (OR per 15 degrees increase, 1.19; 95% CI 1.03-1.37). CONCLUSIONS: Older women with greater degrees of kyphosis are likely to have other manifestations of spinal osteoporosis such as height loss and thoracic fractures and to suffer chronic upper and middle back pain. Measurement of kyphosis may be useful in assessing the severity of spinal osteoporosis.

Age Factors↗
PubMed1997

Racial differences in bone density between young adult black and white subjects persist after adjustment for anthropometric, lifestyle, and biochemical differences.

This study tested whether racial differences in bone density can be explained by differences in bone metabolism and lifestyle. A cohort of 402 black and white men and women, ages 25-36 yr, was studied at the Kaiser Permanente Medical Care Program in Northern California, a prepaid health plan. Body composition (fat, lean, and bone mineral density) was measured using a Hologic-2000 dual-energy x-ray densitometer. Muscle strength, blood and urine chemistry values related to calcium metabolism, bone turnover, growth factors, and level of sex and adrenal hormones were also measured. Medical history, physical activity, and lifestyle were assessed. Statistical analyses using t- and chi-square tests and multiple regression were done to determine whether racial difference in bone density remained after adjustment for covariates. Bone density at all skeletal sites was statistically significantly greater in black than in white subjects; on average, adjustment for covariates reduced the percentage density differences by 42% for men and 34% for women. Adjusted bone density at various skeletal sites was 4.5-16.1% higher for black than for white men and was 1.2-7.3% higher for black than for white women. We concluded that racial differences in bone mineral density are not accounted for by clinical or biochemical variables measured in early adulthood.

Adult↗
PubMed1997

Low thyrotropin levels are not associated with bone loss in older women: a prospective study.

The relationship between excess thyroid hormone and bone loss is controversial. To determine whether low TSH levels, indicating excessive thyroid hormone, are associated with low bone mass or accelerated bone loss in older women, we performed a prospective cohort study of 458 women over age 65 yr participating in the multicenter Study of Osteoporotic Fractures. Three hundred and twenty-three women were randomly selected from the entire cohort of 9704; an additional 135 randomly selected thyroid hormone users were studied. Medical history, medication use, and calcaneal bone mineral density (BMD) were assessed at the baseline visit. Serum was collected and stored at -190 C. Hip and spine BMD were measured approximately 2 yr later, and follow-up calcaneal and hip BMD measurements were obtained after mean follow-up periods of 5.7 and 3.5 yr, respectively. TSH levels were determined in baseline serum samples using a third generation chemiluminescent assay. After adjustment for age, weight, previous hyperthyroidism, and use of estrogen, bone loss over 4-6 yr was similar in women with low, normal, or high TSH. For example, femoral neck bone loss was -0.3%/yr (95% confidence interval, -0.8%, 0.3%) among women with low TSH (< or = 0.1 mU/L) and -0.5%/yr (95% confidence interval, -0.7%, -0.3%) in those with normal TSH (0.1-5.5 mU/L). There were no statistically significant differences in baseline bone mass of the calcaneus, spine, or femoral neck or trochanteric hip subregions. Baseline total hip BMD was 6% lower (P = 0.01) in women with low TSH. Similar results were obtained in analyses confined to women not taking estrogens. We found no consistent evidence that low TSH, a sensitive biochemical marker of excess thyroid hormone, was associated with low BMD or accelerated bone loss in older ambulatory women.

Aged↗
PubMed1996

Randomized controlled trial of a low animal protein, high fiber diet in the prevention of recurrent calcium oxalate kidney stones.

Low protein diets are commonly prescribed for patients with idiopathic calcium nephrolithiasis, who account for > 80% of new diagnoses of kidney stones. This dietary advice is supported by metabolic studies and epidemiologic observational studies but has not been evaluated in a controlled trial. Using 1983-1985 data from three Northern California Kaiser Permanente Medical Centers, the authors randomly assigned 99 persons who had calcium oxalate stones for the first time to a low animal protein, high fiber diet that contained approximately 56-64 g daily of protein, 75 mg daily of purine (primarily from animal protein and legumes), one-fourth cup of wheat bran supplement, and fruits and vegetables. Intervention subjects were also instructed to drink six to eight glasses of liquid daily and to maintain adequate calcium intake from dairy products or calcium supplements. Control subjects were instructed only on fluid intake and adequate calcium intake. Both groups were followed regularly for up to 4.5 years with food frequency questionnaires, serum and urine chemistry analysis, and abdominal radiography; and they were urged to comply with dietary instructions. In the intervention group of 50 subjects, stones recurred in 12 (7.1 per 100 person-years) compared with two (1.2 per 100 person-years) in the control group; both groups received a mean of 3.4 person-years of follow-up (p = 0.006). After adjustment for possible confounding effects of age, sex, education, and baseline protein and fluid intake, the relative risk of a recurrent stone in the intervention group was 5.6 (95% confidence interval 1.2-26.1) compared with the control group. The authors conclude that advice to follow a low animal protein, high fiber, high fluid diet has no advantage over advice to increase fluid intake alone.

Adult↗
PubMed1996

Reduced mortality associated with long-term postmenopausal estrogen therapy.

OBJECTIVE: To compare all-cause and specific-cause mortality rates in women who had or had not used long-term postmenopausal estrogen replacement therapy (ERT). METHODS: We identified women who used long-term postmenopausal ERT and compared them with a sample of age-matched postmenopausal nonusers. Through linking of these subjects' medical record numbers to various data bases, we examined survivorship and cause of death among estrogen users and nonusers. The risk of death in 232 postmenopausal women who began ERT within 3 years of menopause and used it for at least 5 years was compared with that of 222 age-matched postmenopausal nonusers. In the users, the mean length of estrogen use was 17.1 years. RESULTS: Statistically significant reductions in all-cause mortality were found in users compared with nonusers. For death from any cause, the age-adjusted relative risk (RR) and associated 95% confidence interval (CI) in estrogen users was 0.54 (0.38-0.76). The reduction in all-cause mortality was largely due to reductions in coronary heart disease (RR 0.40, CI 0.16-1.02) and other cardiovascular disease (RR 0.27, CI 0.10-0.71). Overall cancer mortality was similar in the two groups (RR 0.85, CI 0.46-1.58), although estrogen users had a higher risk of death from breast cancer (RR 1.89, CI 0.43-8.36) and lower risk of death from lung cancer (RR 0.22, CI 0.04-1.15). CONCLUSION: Long-term ERT use is associated with lower all-cause mortality and confers this apparent protection primarily through reduction in cardiovascular disease.

Cause of Death↗
PubMed1996

Bone mass and subtle abnormalities in ovulatory function in healthy women.

Women with occasional anovulatory or short luteal phase menstrual cycles have been reported to lose bone mineral density (BMD) at a greatly accelerated rate compared to women without such abnormalities. To investigate this association, we performed a longitudinal study of BMD in a group of healthy premenopausal women enrolled in a comprehensive study of ovulatory function. Subjects had collected daily urine samples that were analyzed for estrone and progesterone metabolites by enzyme-linked immunoassay. The 53 participants collected urine for an average of 4.1 cycles. Computer algorithms identified 7 (13.2%) women with luteal phase abnormalities (> 1 anovulatory cycle or cycle with luteal phase length < or = 10 days) and 17 (32.1%) women with other menstrual abnormalities. Areal BMD (grams per cm2) was measured at the lumbar spine, hip, and whole body using dual energy x-ray absorptiometry; BMD was measured 2-3 times over an average observation period of 17.5 months. At baseline, women with luteal abnormalities had mean BMD similar to those of the 29 women with no abnormal cycles: lumbar spine, 1.06 vs. 1.09 g/cm2; total hip, 0.95 vs. 0.94 g/cm2; whole body, 1.15 vs. 1.11 g/cm2 (P > 0.10; adjusted for age and weight at baseline, parity, physical activity level, and calcium intake). When compared at follow-up to women with no abnormal cycles, women with luteal abnormalities tended to gain BMD at the spine and hip (P > 0.10). On whole body measurement, women with luteal abnormalities tended to lose BMD compared to women with no abnormal cycles (-1.1%/yr vs. 0%/yr; P = 0.08); however, the magnitude of loss was not unusual for women in this age range and was within the coefficient of variation for replicate measurements. Neither mean luteal phase length, percent time in luteal phase, nor average daily excretion of progesterone metabolites was associated with baseline BMD or percent annual change in BMD at any measurement site. Thus, we did not confirm a relationship between luteal abnormalities and accelerated bone loss in this population of healthy premenopausal women.

Adolescent↗
PubMed1996

Prevalence of hypothalamic-pituitary imaging abnormalities in impotent men with secondary hypogonadism.

PURPOSE: Because prevalence of structural lesions of the pituitary and hypothalamus in impotent men with secondary hypogonadism was undefined, we evaluated 164 men 27 to 79 years old whose chief complaint was erectile dysfunction and who repeatedly had low serum testosterone levels (less than 230 ng./dl.). MATERIALS AND METHODS: With computerized tomography or magnetic resonance imaging of the sella we detected potentially serious lesions (pituitary lesions greater than 5 mm. or any hypothalamic lesion) in 11 men (6.7%, 95% confidence interval 2.9 to 10.5%), including 5 pituitary microadenomas (5 mm. or larger), 4 pituitary macroadenomas and 2 hypothalamic lesions. RESULTS: Mean serum testosterone was lower in patients with (121 +/- 66 ng./dl., standard deviation) than without (177 +/- 39 ng./dl.) hypothalamic or pituitary imaging abnormalities (p < 0.001). For every 10 ng./dl. decrease in testosterone the risk of hypothalamic or pituitary imaging abnormalities increased 1.2-fold (p < 0.005). Macroadenomas and hypothalamic lesions were confined to 6 subjects with testosterone levels of 104 ng./dl. or less. CONCLUSIONS: The risk of hypothalamic or pituitary imaging abnormalities is low among men evaluated for erectile dysfunction and secondary hypogonadism. However, this risk increases markedly when the serum testosterone level is markedly decreased.

Adult↗
PubMed1996

Technical performance evaluation of BM/Hitachi 747-200 serum fructosamine assay.

The technical performance of serum fructosamine assay as a short-term index of diabetic control was evaluated by using the BM/Hitachi 747-200 Automatic Analyzer (Boehringer Mannheim Corp). Intra- and interassay precisions (CV) were <2%. Linearity was confirmed up to 1000 micromol/L. Lipemia, produced artificially or from hypertriglyceridemia in vivo, did not interfere with measurement of serum fructosamine concentration. However, hemoglobin (Hb) interfered with measurement substantially at concentrations >15.5 micromol/L, and bilirubin interfered substantially at concentrations >68.4 micromol/L. A normal reference range of up to 282 micromol/L (mean +/- 2SD = 242 +/- 40) was derived from results obtained from 228 nondiabetic subjects. In 222 diabetic subjects, serum fructosamine concentration correlated well with fasting glucose concentration (r = 0.74) and with Hb A1c concentration (r = 0.80). This automated fructosamine assay has the advantages of technical simplicity, low cost, and reduced analytical time compared with the Hb A1c method.

Autoanalysis↗
PubMed1995

Estrogen replacement therapy and fractures in older women. Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To determine the relation between estrogen replacement therapy and fractures. DESIGN: Prospective cohort study. SETTING: Four clinical centers in Baltimore County, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela Valley, Pennsylvania. PARTICIPANTS: 9704 ambulatory, nonblack women 65 years of age or older. MEASUREMENTS: Estrogen use, medical history, and anthropometric data were obtained by questionnaire, interview, and examination. Appendicular bone mass was measured by single-photon absorptiometry. Incident fractures were validated by radiographic report. RESULTS: After adjustment for potential confounders, current estrogen use was associated with a decrease in the risk for wrist fractures (relative risk [RR], 0.39; 95% CI, 0.24 to 0.64) and for all nonspinal fractures (RR, 0.66; CI, 0.54 to 0.80) when compared with no estrogen use. Results were similar for women using unopposed estrogen or estrogen plus progestin, for women younger or older than 75 years of age, and for current smokers or nonsmokers. The effect of estrogen remained after adjustment was made for appendicular bone mass. The relative risk for hip fracture tended to be lower among current users (RR, 0.60; CI, 0.36 to 1.02) than among never-users. Estrogen was most effective in preventing hip fracture among those older than 75 years. Current users who started estrogen within 5 years of menopause had a decreased risk for hip fractures (RR, 0.29; CI, 0.09 to 0.92), wrist fractures (RR, 0.29; CI, 0.13 to 0.68), and all nonspinal fractures (RR, 0.50; CI, 0.36 to 0.70) when compared with women who had never used estrogen. Previous use of estrogen for more than 10 years or use begun soon after menopause had no substantial effect on the risk for fractures. CONCLUSIONS: Current use of estrogen appears to decrease the risk for fracture in older women. These results suggest that for protection against fractures, estrogen should be initiated soon after menopause and continued indefinitely.

Age Factors↗
PubMed1995

Fracture protection provided by long-term estrogen treatment.

The objective of the study was to determine the incidence rate of osteoporotic fractures among elderly women who had long-term postmenopausal estrogen replacement therapy (ERT) and to compare this with the incidence rate in women who had not used estrogen. In a previous retrospective cohort study based on medical record review in 1982, we showed that long-term ERT was associated with lower incidence of wrist and vertebral fractures. We have extended our follow-up of 490 women by adding a mean 8 years to the observation period, which more than triples the number of osteoporotic fractures. At the Kaiser Permanente Medical Center, San Francisco, a large health maintenance organization, a review of computer pharmacy records from 1968 through 1971 identified 245 postmenopausal women; all had begun estrogen within 3 years of menopause and had used estrogen for at least 5 years. From the same pharmacy records, 245 age-matched postmenopausal non-users were identified. Among estrogen users, mean length of use was 17.0 years, mean follow-up after treatment was 7.3 years and mean dose of conjugated oral estrogen was 0.9 mg daily. We found statistically significant reduction in the incidence of wrist and vertebral fractures in users compared with non-users. The age-adjusted incidence ratios (95% confidence intervals for wrist fractures were 0.55 (0.32-0.92) and for vertebral fractures were 0.57 (0.41-0.80). These results were not statistically significantly altered after adjustment for age of menopause, body mass index and smoking. It is concluded that long-term ERT confers statistically significant protection against wrist and vertebral fractures.

Estrogen Replacement Therapy↗
PubMed1995

Spinal bone mineral loss in estrogen-replete, calcium-replete premenopausal women.

After peak bone mass in women is attained, the benefits of increased dietary calcium or supplemental calcium are uncertain. In a longitudinal, 4-year study we have investigated the effect of calcium intake on bone mineral in a group of 41 premenopausal women, aged 38-42 years at entry. Skeletal density was measured four times during the 4-year follow-up; spinal trabecular bone density (STBD) was measured by quantitative computed tomography, and midradius bone mineral density (RBMD) was measured by single photon absorptiometry. At baseline, no differences in bone density were observed among subjects in the highest and lowest quartiles of habitual dietary intake. Overall, STBD declined -0.86 +/- 0.15% per year (p < 0.001), but RBMD did not decline. Total calcium intake (dietary calcium plus supplemental calcium) did not correlate with the rate of STBD loss. Serum estradiol level did not decrease during the study, and bone loss did not correlate with the mean estradiol level. We conclude that premenopausal women in the fifth decade lose about 1% of spinal trabecular mineral yearly, in spite of a normal serum estradiol level and ample calcium intake.

Adult↗
PubMed1994

Kyphosis in older women and its relation to back pain, disability and osteopenia: the study of osteoporotic fractures.

To test the hypothesis that thoracic kyphosis is associated with substantial pain, disability, and height loss, we measured thoracic curvature, using an architect's flexicurve, of 610 women aged 65-91 years who were recruited from population-based listings. We assessed study subjects for back pain, back-related disability, height loss since age 25 years, perceived state of health, and bone mineral density (BMD) at the spine, calcaneus, proximal radius, and distal radius. Compared with the rest of the cohort, the 10% of women with the most severe kyphosis had 7%-17% lower BMD (p < 0.001) and had lost an additional 2.4 cm height (p < 0.001). However, kyphotic women had no greater back pain, disability caused by back problems, or poorer health. This cross-sectional study suggests that kyphosis is associated with decreased BMD and loss of height but does not cause substantial chronic back pain, disability, or poor health in older women.

Aged↗
PubMed1994

Cyclic hormone replacement therapy using quarterly progestin.

OBJECTIVES: To determine whether cyclic progestin, when part of postmenopausal hormone replacement therapy, can be used quarterly instead of monthly without increasing the risk of endometrial hyperplasia. In addition, we determined whether this hormone replacement therapy regimen produces an acceptable menstrual pattern. METHODS: The subjects were 214 postmenopausal women, mean (+/- standard deviation) age 56.2 +/- 5.4 years, who had regularly used hormone replacement therapy (consisting of Premarin 0.625 mg/day with monthly cyclic medroxyprogesterone, 5 or 10 mg) for a mean of 5.4 +/- 4.5 years (minimum 1 year). The study intervention consisted of changing the subjects' treatment from the usual monthly progestin to four 3-month (ie, quarterly) cycles of medroxyprogesterone, 10 mg/day for 14 days. Endometrial histology was evaluated by doing endometrial biopsies at study outset and after 1 year. Scheduled and unscheduled vaginal bleeding was reported in daily diaries. RESULTS: Endometrial hyperplasia was found in 1.5% of 199 women completing follow-up, a rate similar to the 0.9% prevalence found at baseline. Compared with monthly medroxyprogesterone, quarterly medroxyprogesterone resulted in longer menses (7.7 +/- 2.9 versus 5.4 +/- 2.0 days) and more reports of heavy menses (31.1 versus 8.0%) and unscheduled bleeding (15.5 versus 6.8%). Despite these problems, women preferred the quarterly regimen by nearly four to one. CONCLUSIONS: In a 1-year trial, quarterly medroxyprogesterone appeared as safe as monthly medroxyprogesterone and was preferred by most women. This schedule may be useful for women seeking relief from monthly use of progestin and monthly menses.

Adult↗