Biomedical subjects

M Sowers

Publications and source records attributed to M Sowers.

50 records · Page 3Linked to original sources

PubMed1993

Epidemiology of calcium and vitamin D in bone loss.

Questions remain about the role of diet and skeletal bone loss. There is some indication from studies in premenopausal women that increased dietary calcium intake may be influential in promoting greater peak bone mass, although the evidence is inconsistent. A number of these studies have been reviewed recently. The findings from the clinical trials suggest that calcium supplementation as an effective intervention agent for bone loss in postmenopausal women must be more carefully investigated to identify at-risk women who will benefit from supplementation. The baseline levels of calcium intake and years since menopause should be considered. There is potential for a mild-to-moderate vitamin D deficiency leading to occult osteomalacia that contribute significantly to the excess bone loss and fracture observed in Caucasian women: The effects of diet, specific nutrients and metabolic bone disease may be difficult to ascertain when either the nutrient exposure is not well characterized or when the disease outcome is not well characterized. Additional work is needed to describe the relative influence of nutrient intake at different stages of the life cycle, the interactive nature between nutrients as they are expressed in bone metabolism and the role of nutrients according to level of hormones and exercise.

Calcium↗

PubMed1993

Periodontal disease in an Amish population.

Epidemiological studies of periodontal disease have attempted to focus on defined groups in which the variables thought to be responsible for disease could be controlled or more easily identified. This study documents periodontal disease parameters in a unique population of Amish farmers. A total of 371 Amish were contacted and 282 were examined in their homes giving a participation rate of 76%. Ages ranged from 18 to 79 years. Overall means for periodontal conditions were 1.54 mm for attachment loss, 2.63 mm for pocket depth, 0.17 for calculus, 0.63 for plaque and 0.61 for gingivitis. One dental examiner conducted all examinations. Prevalence of periodontal disease tended to be higher among males and increased with age. The majority of Amish examined had little evidence of destructive periodontal disease; about 3.4% of teeth examined had attachment loss of 6 mm or more. These findings indicate a modest level of periodontal disease among the Amish. It is of interest that this population does not generally seek routine dental care. Preliminary analyses of health behavior data collected indicate a lack of regular oral hygiene practices. It appears that the Amish may have protective factors which affect their level of disease.

Adolescent↗

PubMed1992

Historical changes in serum PCB and DDT levels in an environmentally-exposed cohort.

A previously characterized cohort of 115 Great Lakes fisheaters and 95 non-fisheating controls was re-examined in 1989 to evaluate changes that had occurred in serum PCB and DDT levels since the 1982 study. Substantial and significant decreases in mean serum DDT levels had occurred in both fisheaters (25.8 ppb vs 15.6 ppb) and controls (9.6 ppb vs 6.8 ppb) over this time period. In contrast, only a slight decrease in serum PCB levels was observed, and in fisheaters only. No association between individual changes in serum PCB or DDT levels and self-reported changes in Great Lakes fish consumption was observed. The findings from this longitudinal examination of serum PCB and DDT levels confirm earlier cross-sectional surveys of western populations, and demonstrate that the prohibition of DDT has been successful in reducing the level of DDT contamination in human populations.

Adult↗

PubMed1992

Systemic hypertension and senile cataracts: an epidemiologic study.

A hospital-based case-control study was conducted at the Allen Park Michigan Veterans Administration Medical Center to determine whether a diagnosis of systemic hypertension was associated with increased risk for senile cataracts. Data from 136 cataract extraction patients were compared to 142 controls. Systemic hypertension was found to increase significantly the risk for posterior subcapsular cataracts. Diabetes mellitus was also associated with increased cataract risk. The use of nonsteroidal anti-inflammatory agents showed a significant protective effect only in the presence of a diagnosis of systemic hypertension.

Aged↗

PubMed1991

The accuracy of self-reported hearing loss in women aged 60-85 years.

The accuracy of self-report in identifying individuals with hearing impairment was evaluated in 1988 in 267 women from rural Iowa. Using pure-tone threshold audiometry as the standard, self-reported hearing loss was a sensitive and specific indicator of measured losses of 40 decibel hearing level for pure-tone averages of either 1,000 and 2,000 Hz or 1,000, 2,000, 3,000 and 4,000 Hz (sensitivities, 90% and 84%; specificities, 71% and 75%, respectively). Predictive values positive were low (28% and 42%) in this population where hearing loss prevalence was 11-18%, but would be increased to acceptable levels in populations with a prevalence of approximately 30%.

Aged↗

PubMed1991

Progression of osteoarthritis of the hand and metacarpal bone loss. A twenty-year followup of incident cases.

We examined the prospective relationship between metacarpal bone mass and osteoarthritis (OA) of the hand, using incidence data from the historical cohort in the Tecumseh Community Health Study (Tecumseh, MI). Women were examined for radiographic evidence of OA and for bone mass twice, 20-23 years apart (1962-1965 and 1985; 683 subjects with an age range of 55-74 in 1985). Two measures of OA were evaluated: the highest score assigned to any of the 32 wrist/hand joints, and the sum of scores for all wrist/hand joints. After adjustment for age, women who were classified as having OA (by either measure of OA) in 1985 were more likely to have more cortical area at baseline, which indicates greater bone mass. Women who developed OA in the 23-year period were more likely to experience a significantly greater widening of the medullary cavity over time, an indicator of increased bone resorption. Women with increasing levels of OA involvement also had an increased likelihood of greater cortical area loss. We conclude that women who later developed OA were more likely to have higher baseline bone mass than women who did not develop OA, but these women also had a greater likelihood of bone loss over time.

Adult↗

PubMed1991

Prospective study of radial bone mineral density in a geographically defined population of postmenopausal Caucasian women.

The radial bone mineral density (BMD) mass of 324 Caucasian women, aged 55-80 years, from geographically defined areas was evaluated in 1983 using single photon absorptiometry; 271 of these women (86%) were reexamined 5 years later in 1988. More than 65% of women lost radial BMD in excess of 1%/year in the 5-year follow-up. Thirty percent of women lost at least 2%/year. Baseline radial BMD measures taken in 1983 were highly predictive of the 1988 radial BMD values, explaining approximately 82% of the variability. The rate of bone change, expressed as percent change or 5-year difference (g/cm2), was not associated with baseline radial BMD value. Rate of change was not strongly associated with chronologic age or years since menopause, even when data were restricted to those women who reported no previous use of perimenopausal estrogen or thiazide medication. We conclude that BMD loss in a general population may be more substantial than previously believed.

Absorptiometry, Photon↗

PubMed1991

Body composition, age and femoral bone mass of young adult women.

Maximum bone mineral density of the femur was measured by dual-photon densitometry in 282 healthy white women, aged 20 to 40 years. Femoral sites included the neck, Wards triangle, and the trochanter. Quetelet Index was used as a measure of weight adjusted for height, and body composition was measured using four-point bioelectrical impedance and anthropometry. Maximum bone mass is believed to be an important measure if the level established which remain characteristic or predict bone mineral density during the aging process. Body weight was correlated with each measure of femoral bone density, including the femoral neck (r = .42), Wards triangle (r = .34), and the trochanter (r = .44). Weight was more highly correlated with bone mass than with other measures of body composition, including fat-free mass, percent body fat, humeral muscle area, and humeral fat area. We observed that age was negatively associated with bone mass at all three femoral sites, even in subjects within the age range of 20 to 40 years, and the relationship was significant after controlling for Quetelet Index. There was no evidence of a nonlinear relationship that would indicate when maximal femoral bone mass reaches its peak within this age range.

Adult↗

PubMed1991

A prospective evaluation of bone mineral change in pregnancy.

During pregnancy, mineralization of the fetal skeleton creates a demand for approximately 30 g of calcium from maternal sources. We examined whether this fetal demand results in maternal femoral bone mineral loss. Femoral bone mineral density was measured twice by dual photon densitometry, once before conception and again within 15 days of parturition, in 32 white women aged 20-40 years. Femoral bone mineral density was also measured twice in 32 non-pregnant controls matched to the cases for weight, height, age, and parity. There was no significant mean bone mineral density loss in cases compared with controls (P greater than .63). Pregnant women with smaller body size, expressed as Quetelet index, were more likely to have femoral neck bone mass increase than their matched controls (P less than .03). This study provides evidence that fetal demand for calcium has a minimal effect on bone mineral density at parturition. Smaller women may experience a slight increase in femoral bone mineral density compared with controls.

Adult↗

PubMed1986

A method to assess sodium intake in populations.

Dietary sodium measurement in populations has severe limitations whether assessment is based on urinary excretion or on food intake methods. We have validated a simple instrument to determine total dietary sodium intake of populations in a pilot study of 10 women, 20 to 36 years old. Sodium intake determined by means of the sodium measurement instrument was correlated with sodium intake from food analysis, sodium intake calculated from food composition tables, and measurement of 24-hour urinary sodium excretion. Sodium values obtained with the instrument are based on regression equations, which incorporate information as follows: an average measure of 7 days' actual table salt use, the average sodium contribution of 17 high-sodium foods from a food frequency checklist maintained for 7 days, a calculation of drinking water sodium, and measurements of height and weight to establish 24-hour energy needs, a surrogate estimate of sodium found in all foods not included in the food frequency checklist. Participants were studied for 16 days: 7 consecutive days on either a 2,000-mg or a 3,500-mg sodium diet, 2 days' adjustment, and 7 days' crossover. Participants were allowed to select foods from a diverse menu, eat at fast-food restaurants, and consume alcohol if desired. Mean of 7-day sodium intake obtained with the instrument was significantly correlated with mean of 7-day sodium intake determined by food analysis (r = .80), from food composition tables (r = .62), and from urinary excretion (r = .56).

Adult↗

PubMed1985

Correlates of forearm bone mass among women during maximal bone mineralization.

The distribution and correlates of bone mass among women ages 20-35 were studied. During young adulthood, bone mass reaches its maximum level and appears to stabilize. Factors that establish the individual's relative position in this plateau period may influence the ultimate expression of bone loss with aging. Mid-distal radial bone mass was measured in a geographically defined population of 86 women in two rural, demographically similar communities in Iowa. The water supplies provided 55 and 375 mg/liter of elemental calcium, generating significantly different mean community dietary calcium intakes of 871 and 1,233 mg/day, respectively. Bone mass was measured by single-beam photon densitometry and correlated with data from physical measurements, medical history, and reported nutritional intake. In evaluating the joint effect of variables in a multiple regression procedure, forearm bone mass was negatively and significantly associated with alcohol consumption (P = 0.0327) and with a first pregnancy prior to age 20 (P = 0.0250). There was a trend for current calcium intake estimated from 24-hr recall to be positively associated with bone mass (P = 0.0816). Because the 24-hr recall is characterized by significant error due to daily variability of an individual's intakes, a more general calcium intake was estimated from food frequency. Women whose estimated intake of calcium from food frequency was greater than 800 mg/day, the Recommended Daily Allowance, had significantly greater bone mass than women whose intake was estimated to be less than 800 mg/day (P = 0.0053). No relationship was observed with oral contraceptive use, parity, breastfeeding practices, smoking behavior, or measures of physical activity.

Adult↗

PubMedDate not supplied

Interpregnancy weight retention patterning in women who breastfed.

This study compares weight change in lactating women with an 18-month interpregnancy interval with woman who also breastfed but did not have an immediate subsequent pregnancy. Cases were women who breastfed an index infant for 6 months and subsequently became pregnant within 18 months (cases = 25), and the controls also breastfed an index infant for 6 months but had no ensuing pregnancy (controls = 20) within 18 months. The pattern of postpartum weight retention following the initial pregnancy was not statistically different in cases compared to the controls. However, following their ensuing subsequent pregnancy, cases were 1.3 kg heavier than their average weight after their baseline pregnancy (P = 0.02). The best predictor of this greater weight was their weight change during the interpregnancy interval (P = 0.03). Total weight gain during the gestational period of the subsequent pregnancy was not associated with the greater weight following the subsequent pregnancy. Likewise, estimates of the amount of energy as calories or physical activity levels were not significant predictors of this greater weight following the subsequent pregnancy. These findings suggest that monitoring of postpartum weight, even in breastfeeding women, is essential. These findings indicate that breastfeeding women begin the next postpartum interval weighing more than the amount observed in the initial postpartum period.

Adult↗

PubMedDate not supplied

Environmental exposure and lifestyle predictors of lead, cadmium, PCB, and DDT levels in Great Lakes fish eaters.

A previously characterized cohort of 115 Great Lakes fish eaters and 95 non-fish-eating regional controls was reexamined in 1989. Levels of blood lead and cadmium and serum PCB and DDT were measured. Lifestyle characteristics, including recent and historic fish consumption, were evaluated as predictors of contaminant levels using multivariate regression analysis. Significantly elevated serum PCB and DDT levels were observed in fish eaters, compared with controls. Historic fish consumption, rather than recent consumption, was identified as the primary predictor of current serum levels. Mean blood lead and cadmium were also significantly higher in fish eaters than in controls. However, the primary predictors of lead and cadmium were behavioral exposures--specifically smoking and self-reported occupational and recreational exposure-rather than fish consumption. These findings illustrate the importance of evaluating a variety of possible sources when investigating human exposure to environmental contaminants.

Adult↗

PubMedDate not supplied

Changes in bone density with lactation.

OBJECTIVE: To test the a priori hypotheses that significant bone loss occurs in lactation of greater than 5 months' duration and that bone mass returns to baseline levels when breast-feeding ceases. DESIGN: Prospective cohort study design of 12 months' duration. SETTING: General community setting with recruitment occurring at birthing education classes. PARTICIPANTS: Volunteer sample of 98 healthy women of white (n = 95) and Asian (n = 3) origin, aged 20 to 40 years, and 0 to 1 parity prior to parturition, grouped according to lactation duration: 0 through 1, 2 through 5, and 6 or more months. MAIN OUTCOME MEASURES: Bone mineral density (BMD) of the proximal femur was measured by dual-energy x-ray densitometry at 2 weeks (baseline), 2 months, 4 months, 6 months, and 12 months following parturition, and BMD of the lumbar spine was measured at baseline, 6 months, and 12 months after parturition. RESULTS: Women with lactation duration of 6 months or longer had mean BMD losses of 5.1% and 4.8% at the lumbar spine and femoral neck, respectively, comparing baseline values with those at 6 months post partum. Women who breast-fed 0 through 1 month lost no BMD at either bone site. Bone loss in women who breast-fed 6 months or longer was not explained by differences in age, diet, body size, or physical activity. Among women who breast-fed 6 months or longer, there was evidence of return to baseline levels of the lumbar spine at 12 months after parturition. The BMD of the lumbar spine of those women who continued to breast-feed more than 9 months had increased but was still significantly lower than baseline. CONCLUSION: Extended lactation (> or = 70% of energy intake is provided for > or = 6 months) is associated with bone loss; however, there is evidence of return to baseline BMD measurement at 12 months after parturition.

Absorptiometry, Photon↗