Biomedical subjects

W M O'Fallon

Publications and source records attributed to W M O'Fallon.

At least 217 records · Page 12Linked to original sources

PubMed1992

Conditions associated with carpal tunnel syndrome.

With use of a comprehensive medical records-linkage system, we identified the comorbid conditions and risk factors in the residents of Rochester, Minnesota, who had a diagnosis of carpal tunnel syndrome during 1961 through 1980. In 43.2% of the 1,016 patients, no associated conditions were found on review of the medical records, whereas associated conditions were documented in 56.8%. The most frequent of these conditions were Colles' fracture, rheumatoid arthritis, hormonal agents or oophorectomy (or both), diabetes mellitus, and, among men, occupations that involved excessive use of the hands. Rheumatoid arthritis, diabetes mellitus, and pregnancy were significantly more frequent among the study patients with carpal tunnel syndrome than in the general population of Rochester, Minnesota. The standardized morbidity ratio was 3.6 for rheumatoid arthritis, 2.3 for diabetes mellitus, and 2.5 for pregnancy. The population attributable risk for pregnancy among women 15 to 44 years old was 7.0%. The standardized morbidity ratio for polymyalgia rheumatica was not significantly increased.

Adolescent↗

PubMed1992

Fracture risk in patients with parkinsonism: a population-based study in Olmsted County, Minnesota.

In this population-based retrospective cohort study, the 138 Olmsted County, Minnesota residents first diagnosed with Parkinson's disease during 1967-79 were matched by age and sex to an equal number of control subjects from the community. Fractures were assessed through review of each subject's complete (inpatient and outpatient) medical records. At the time of diagnosis, County residents with parkinsonism were no more likely to have a history of selected fractures than control subjects (32% in each group). Subsequently, 33% of cases and 20% of controls experienced one or more new fractures during 696 person-years of follow-up (p = 0.008). The greatest increase in risk was seen for proximal femur fractures, confirming previous case-control studies. By 10 years after diagnosis, an estimated 27% of the parkinsonism cohort had experienced a new hip fracture. The pattern of fractures that was observed suggested that the increased risk was due more to specific types of falls than to disuse osteoporosis.

Aged↗

PubMed1992

Relationship of cardiac disease to stroke occurrence, recurrence, and mortality.

BACKGROUND AND PURPOSE: This is a study of cardiac diseases associated with the 1,382 cases of first cerebral infarction in residents of Rochester, Minn., during 1960-1984. METHODS: This is a population-based study in Rochester, Minn., for which the medical record-linkage system was used to identify cardiac disease among patients with first cerebral infarction. RESULTS: There were 318 patients (23%) who had at least one major potential cardiac source of emboli. The proportion of patients with a cardiac source of emboli was significantly higher among patients older than age 75 years (29%) than among younger patients (17%). The 30-day stroke recurrence rate among patients with a cardiac source of emboli (2%) was not significantly different than that among those without a cardiac source of emboli (2%). Among patients with a cardiac source of emboli, there was no difference in the probability of stroke at 30 days and at 90 days for those treated or not treated with anticoagulants. During the first 30 days after cerebral infarction, the risk of death in patients with a cardiac source of emboli (23%) was 14 times that of recurrent stroke. The risk of death at 30 days in patients without a cardiac source of emboli was 8%. CONCLUSIONS: Significant independent predictors of death (Cox proportional-hazards analysis) were age, prior myocardial infarction, atrial fibrillation present at onset of stroke, congestive heart failure before the stroke, and an age x congestive heart failure interaction. The only significant independent predictors of recurrent stroke were cardiac valve disease and congestive heart failure.

Cerebrovascular Disorders↗

PubMed1992

A community-based study of the epidemiology of asthma. Incidence rates, 1964-1983.

To determine whether the incidence of asthma had increased in Rochester, Minnesota, from January 1, 1964 through December 31, 1983, we used a population-based computer-linked medical diagnosis system to identify individual medical records with diagnosis of asthma or other conditions mimicking asthma. All records were reviewed using explicit predetermined diagnostic criteria; we identified 3,622 incident cases of asthma, including definite asthma (n = 1,547), probable asthma (n = 952), and single wheezing episodes (n = 1,123). The annual age- and sex-adjusted incidence of definite + probable asthma rose from 183 per 100,000 in 1964 to 284 per 100,000 in 1983. This rise was entirely accounted for by increased incidence rates in children and adolescents (age range, 1 to 14 yr); incidence rates for infants younger than 1 yr of age and for adults remained constant. For definite + probable asthma cases, the incidence rates for males were higher than for females from infancy through 9 yr of age and for persons older than 50; incidence rates for females were higher than for males from 15 through 49 yr of age. The median age at onset was 3 yr for males and 8 yr for females. We conclude that asthma begins in early childhood, with a higher incidence and earlier onset in males, and that the increase in incidence rates seen from 1964 to 1983 occurred only in children and in adolescents.

Age Factors↗

PubMed1992

Incidence of migraine headache: a population-based study in Olmsted County, Minnesota.

To determine the incidence of clinically detected migraine headache in the defined population of Olmsted County, MN, 1979-1981, we screened over 6,400 patient records from several diagnostic rubrics using the unique resources of the Rochester Epidemiology Project for population-based studies. We identified 629 Olmsted County residents who fulfilled the International Headache Society's 1988 criteria for newly diagnosed migraine headache between 1979 and 1981. The overall age-adjusted incidence was 137 per 100,000 person-years for males and 294 per 100,000 person-years for females. The highest incidence in females was among those aged 20 to 24 years (689 per 100,000 person-years), and in males, the highest incidence was among those aged 10 to 14 years (246 per 100,000 person-years). From 1979 to 1981, there was a striking increase in the age-adjusted incidence in those under 45 years of age: the incidence increased 34% in women and 100% for men. This is the first population-based study of migraine incidence across all ages.

Adolescent↗

PubMed1992

Dialysis support of patients with primary systemic amyloidosis. A study of 211 patients.

BACKGROUND: The study assessed dialysis support in patients with primary systemic amyloidosis without associated multiple myeloma in whom renal insufficiency developed. METHODS: The study group consisted of 211 patients with biopsy-proved primary systemic amyloidosis examined at the Mayo Clinic, Rochester, Minn. No patient was lost to follow-up. RESULTS: Thirty-seven (18%) of the patients received dialysis therapy. Of those presenting with renal amyloid, one third received dialysis. The median time from diagnosis to initiation of dialysis was 13.8 months. The median survival for patients from the start of dialysis was 8.2 months. There was no survival difference between hemodialysis (n = 27) and peritoneal dialysis (n = 10). The most important predictors of which patients would ultimately require dialysis were the 24-hour urinary protein loss and serum creatinine values at the time amyloidosis was diagnosed. None of the patients seen at diagnosis with a normal serum creatinine value and proteinuria of less than 2 g/d required dialysis during follow-up. Of the 37 patients who received dialysis, 31 died, and 21 of the 31 died as a result of extrarenal progression of their systemic amyloidosis. Fifteen of the 31 deaths were a result of cardiac amyloidosis. All long-term survivors had normal echocardiograms without evidence of amyloid. CONCLUSION: Eighteen percent of patients with primary amyloidosis undergo dialysis. The 24-hour urinary protein loss and creatinine values are helpful in predicting which patients eventually will require dialysis. The median survival for patients starting dialysis is less than 1 year. Patients whose two-dimensional echocardiograms are normal are most likely to derive long-term benefit from dialysis.

Aged↗

PubMed1992

Risk of age-related fractures in patients with primary hyperparathyroidism.

BACKGROUND: Bone mass is reduced, but the influence of primary hyperparathyroidism (HPT) on fracture risk is controversial. We addressed this issue in a population-based retrospective cohort study. METHODS: Ninety residents of Rochester, Minn, were first diagnosed with HPT in 1965 through 1976 and an equal number of age- and sex-matched control subjects from the community were identified. Fractures were assessed through review of each subject's complete (inpatient and outpatient) medical records in the community. RESULTS: Prior to the date of diagnosis, Rochester residents with HPT were more likely to have a history of fractures than were matched control subjects from the same population (30% vs 18%). Subsequently, 36% of cases and 31% of control subjects experienced one or more new fractures during 1072 person-years of follow-up; survival free of a new fracture was almost the same in the two groups. Women had more fractures than men, and fracture rates increased with age. Fractures appeared to be somewhat more frequent in those with baseline serum calcium levels of 2.74 mmol/L or more, in those with comorbid conditions possibly due to HPT and in those who did not undergo parathyroidectomy, but these differences were not statistically significant. In a multivariate analysis, only age at diagnosis was an independent predictor of fracture risk, with a 36% increase in risk per 10-year increase in age. CONCLUSIONS: Overall fracture risk was increased prior to diagnosis of HPT but not afterward. Because the numbers involved were small, however, we cannot exclude an increased likelihood of fractures in certain subgroups of HPT patients.

Age Factors↗

PubMed1992

Epidemiology of Lyme disease in Olmsted County, MN, 1975-1990.

Lyme disease has been reported in Minnesota since 1980. Until now, it has not been regarded as endemic in Olmsted County. We reviewed the medical records of all 68 cases of Lyme disease diagnosed in residents of Olmsted County for 1980-1990. Only 17 of the 68 cases met Centers for Disease Control surveillance criteria for definite Lyme disease (13 men, 4 women). Of these 17 cases, 3 were likely acquired in Olmsted County. The age and sex adjusted incidence rate was 2.3/100,000 (95% CI 1.1-3.4). Although reporting of Lyme disease is mandatory in Minnesota, only 7 suspected or definite cases were actually reported to public health officials. Of these, 4 met the case definition. In this population Lyme disease was both over-diagnosed and underreported. This observation questions current data and could have important health policy implications if confirmed nationally.

Adolescent↗

PubMed1991

Predictors of intracranial carotid artery atherosclerosis. Duration of cigarette smoking and hypertension are more powerful than serum lipid levels.

The effect of cigarette smoking on intracranial internal carotid artery atherosclerosis (ICAS) was studied by obtaining cigarette smoking histories and data on other potential predictors, including serum lipid estimations, for consecutive patients undergoing carotid arteriography. The duration of cigarette smoking was the most significant independent predictor of the presence of ICAS. Other independently significant predictors of ICAS were hypertension, diabetes mellitus, and current systolic blood pressure. The interaction of diabetes and duration of smoking was a significant negative predictor. In patients for whom serum lipid values were available, lower levels of apolipoprotein A-I were associated with a higher risk of having ICAS. However, the effect of apolipoprotein A-I as a predictor of the presence of ICAS was far outweighted by the effects of duration of smoking and hypertension.

Adult↗

PubMed1991

Serum lipids and lipoproteins are less powerful predictors of extracranial carotid artery atherosclerosis than are cigarette smoking and hypertension.

The effect of serum lipids and lipoproteins on extracranial carotid artery atherosclerosis (CAS) was studied in patients who underwent carotid arteriography. Serum lipid and lipoprotein values along with data on other potential predictors of extracranial CAS were determined in 240 patients who had at least one extracranial carotid artery visualized. In a multiple logistic regression analysis, the independently significant predictors of the presence of extracranial CAS were, in decreasing order of significance, duration of smoking of cigarettes, hypertension, age, and low-density lipoprotein cholesterol. Serum cholesterol, triglycerides, high-density lipoprotein cholesterol, and apolipoprotein A-I did not show an independent effect. Although low-density lipoprotein cholesterol was an independent predictor of the presence of extracranial CAS, its effect as a predictor was far outweighed by the effects of the duration of smoking of cigarettes and a history of hypertension.

Adult↗

PubMed1991

Epidemiological characteristics of lacunar infarcts in a population.

BACKGROUND AND PURPOSE: This study evaluated the characteristics and natural history of patients with lacunar (small, deep) cerebral infarcts in a defined population for comparison of these characteristics to those in patients with nonlacunar infarcts. METHODS: This is a population-based study in Rochester, Minnesota, from 1960 to 1984, that used the medical record-linkage system to identify and characterize patients with cerebral infarction. RESULTS: The age- and sex-adjusted average annual incidence rate of lacunar cerebral infarction was 13.4/100,000 persons, accounting for 12% of all first cerebral infarcts. Temporal trends in incidence rates, stroke recurrence rates, prevalence of diabetes mellitus, and causes of death (given survival for 30 days) for cases of lacunar infarction were not significantly different from those for cases of nonlacunar infarction. Hypertension was found in 81% of patients who had a lacunar infarct and in 70% of patients who had a nonlacunar infarct (p = 0.05). A potential cardiac source of embolism was found in 12% of patients who had a lacunar infarct and in 28% of patients who had a nonlacunar infarct (p = 0.002). Survival was significantly better after a lacunar infarct than after a nonlacunar infarct. CONCLUSIONS: Small, deep cerebral infarcts had many of the epidemiological characteristics of other cerebral infarcts but there was a slightly higher frequency of hypertension, significantly lower frequency of a cardiac embolic source, and significantly better survival in patients with lacunar infarction than in those with nonlacunar infarction.

Cerebral Infarction↗

PubMed1991

50-year trends in the incidence of anorexia nervosa in Rochester, Minn.: a population-based study.

OBJECTIVE: The aim of the study was to determine incidence and prevalence rates and long-term trends in incidence of anorexia nervosa by identifying all persons residing in the community of Rochester, Minn., during the 50-year period 1935 through 1984 who had the disorder. METHOD: From a community-based epidemiologic resource, 13,559 medical records with diagnoses of amenorrhea, starvation, weight loss, anorexia nervosa, or other conditions were screened to identify true cases of anorexia nervosa determined by using standard diagnostic criteria. RESULTS: One hundred eighty-one residents (166 female and 15 male) fulfilled the diagnostic criteria for anorexia nervosa; these were the incidence cases. Due to a quadratic trend in the rates for girls 10-19 years old, the incidence rate among female residents fell from 16.6 per 100,000 person-years in the 1935-1939 period to a low of 7.0 in 1950-1954 and increased to 26.3 in 1980-1984. The incidence rates for women 20 years old and older and for males remained constant. For females 15-24 years old, there was a linear increase. The overall age-adjusted incidence rate per 100,000 person-years was 14.6 for females and 1.8 for males. The prevalence rate per 100,000 population was 269.9 for females and 22.5 for males. CONCLUSIONS: Anorexia nervosa is more common than previously recognized. Among girls 15-19 years old it is a very common chronic illness. Its incidence has increased among females 15-24 years old but not among older women or among males.

Adolescent↗

PubMed1991

Bilateral oophorectomy trends in Olmsted County, Minnesota, 1950-1987.

Over the 38-year period from 1950 through 1987, 1,434 Olmsted County, Minnesota women had a first unilateral oophorectomy, while 1,828 underwent bilateral oophorectomy (including 113 with a second unilateral oophorectomy). Most procedures (61% of unilateral and 87% of bilateral oophorectomies) were in conjunction with hysterectomy, and trends over time paralleled those reported for hysterectomy. Almost half of all operations (27% of unilateral and 63% of bilateral oophorectomies) were elective. The rise in bilateral oophorectomy rates over time (3.7 per 100,000 person-years per year, P = 0.016) was mostly due to elective procedures among older women, with both an increased frequency of surgery and a shift from unilateral to bilateral oophorectomy.

Adolescent↗

PubMed1991

Progression of peripheral occlusive arterial disease in diabetes mellitus. What factors are predictive?

The clinical, biochemical, and vascular laboratory measurements potentially associated with the development and/or progression of peripheral occlusive arterial disease (POAD) were assessed during a 4-year period in 110 normal control subjects, 112 patients with POAD without diabetes mellitus, 240 patients with diabetes mellitus without POAD, and 100 patients with diabetes mellitus and POAD. Age, history of hypertension or coronary heart disease, history of cigarette smoking, presence of POAD, systolic blood pressure, and beta-thromboglobulin level were associated with progression of POAD. A multivariate logistic regression model indicated that the presence of diabetes mellitus or POAD or both at baseline, decreased postexercise ankle-brachial index, increased arm systolic blood pressure, and current smoking were independently associated with progression of POAD. This study suggests that cessation of smoking and control of hypertension are essential treatment modifications to decrease the risk of progression of peripheral vascular disease in diabetic patients.

Arterial Occlusive Diseases↗

PubMed1990

Effect of fluoride treatment on the fracture rate in postmenopausal women with osteoporosis.

Although fluoride increases bone mass, the newly formed bone may have reduced strength. To assess the effect of fluoride treatment on the fracture rate in osteoporosis, we conducted a four-year prospective clinical trial in 202 postmenopausal women with osteoporosis and vertebral fractures who were randomly assigned to receive sodium fluoride (75 mg per day) or placebo. All received a calcium supplement (1500 mg per day). Sixty-six women in the fluoride group and 69 women in the placebo group completed the trial. As compared with the placebo group, the treatment group had increases in median bone mineral density of 35 percent (P less than 0.0001) in the lumbar spine (predominantly cancellous bone), 12 percent (P less than 0.0001) in the femoral neck, and 10 percent (P less than 0.0001) in the femoral trochanter (sites of mixed cortical and cancellous bone), but the bone mineral density decreased by 4 percent (P less than 0.02) in the shaft of the radius (predominantly cortical bone). The number of new vertebral fractures was similar in the treatment and placebo groups (163 and 136, respectively; P not significant), but the number of nonvertebral fractures was higher in the treatment group (72 vs. 24; P less than 0.01). Fifty-four women in the fluoride group and 24 in the placebo group had side effects sufficiently severe to warrant dose reduction; the major side effects were gastrointestinal symptoms and lower-extremity pain. We conclude that fluoride therapy increases cancellous but decreases cortical bone mineral density and increases skeletal fragility. Thus, under the conditions of this study, the fluoride-calcium regimen was not effective treatment for postmenopausal osteoporosis.

Aged↗

PubMed1990

Cancellous bone remodeling in type I (postmenopausal) osteoporosis: quantitative assessment of rates of formation, resorption, and bone loss at tissue and cellular levels.

The cellular mechanisms for bone loss in type I (postmenopausal) osteoporosis are highly controversial. We attempted to resolve this by assessing rates of formation and resorption of iliac cancellous bone by a new histomorphometric method in 89 women with osteoporosis (mean age +/- SD, 66 +/- 6 years) and in 32 carefully selected normal postmenopausal women (64 +/- 6 years). In the osteoporotic women, bone resorption rate was increased by 39% (P less than 0.05) at the cellular level and by 67% (P less than 0.05) at the tissue level, whereas bone formation was unchanged at the tissue level but decreased by 14% (P less than 0.01) at the cellular (osteoblast) level. This pronounced remodeling imbalance (P less than 0.001) was probably exacerbated by a 45% increase (P less than 0.1) in activation frequency of new remodeling foci. These abnormalities were associated with a high rate of cancellous bone loss (median, 5.8%/year versus 0.1% year in controls). Thus, accelerated loss of cancellous bone in type I osteoporosis results from the combination of increased bone resorption and inadequate compensation by bone formation.

Aged↗

PubMed1990

Effect of age on variables relating to calcium and phosphorus metabolism in women.

Lack of adequate data concerning the effect of age on biochemical variables relating to bone and mineral metabolism hampers research on age-related bone loss in women. Furthermore, to detect disease and to monitor therapy, clinical laboratories require reference values derived from an appropriate population sample. Therefore, we determined the age-specific distribution of values for serum concentrations of calcium, inorganic phosphorus, alkaline phosphatase, bone Gla protein, and parathyroid hormone; for creatinine clearance; for fasting urinary calcium:creatinine ratio; and for 24 h urinary excretion of calcium, hydroxyproline, and cyclic AMP in a population-based sample of 301 white women. From this sample, a healthy subgroup of 181 women was identified by medical record review. Age-related effects were seen in all variables except serum calcium and phosphorus. Moreover, substantial differences between the population sample and the healthy subgroup were noted in values for creatinine clearance, serum alkaline phosphatase, and 24 h urinary calcium excretion. These observations may prove useful for assessment of normality in other populations of aging white women.

Adult↗

PubMed1990

Measurement of vertebral area on spine x-rays in osteoporosis: reliability of digitizing techniques.

Much of the clinical research in osteoporosis is directed toward documenting a reduction in vertebral fracture rate, but there is considerable disagreement about defining and quantifying vertebral fractures. We have evaluated the technique of digitizing landmarks identified on lateral radiographs of thoracic and lumbar vertebrae and computing vertebral body area. Reduction in area indicates that fractures occurred. Radiographs from 10 patients with osteoporosis and vertebral fractures were obtained from each of two centers. Henry Ford Hospital (HFH) and Mayo Clinic (MC), and vertebral area for each individual in the complete set of 20 radiographs was calculated at each center. Measurements at the two centers differed by a multiplicative constant related to the method of recording landmarks on the radiographs that was estimated using 300 x-rays from HFH. After adjusting the MC areas for this multiplicative relationship, the average ratio of the HFH areas to the transformed MC areas of individual vertebrae (T4-L5) ranged from 0.98 to 1.06. The correlation between HFH and transformed MC areas for individual vertebrae averaged 0.85, with slopes between 0.87 and 1.00, intercept average -0.57. Within-patient rank correlation averaged 0.97. We conclude that radiographic digitization is a reliable and reproducible method of determining vertebral body dimensions that is suitable for evaluating radiographs obtained at different clinical sites and for comparison with normal data. This technique should prove useful for documenting the presence of a vertebral fracture that may not be readily apparent on visual inspection of radiographs and for monitoring serial changes in vertebral body dimensions in long-term epidemiologic and therapeutic studies.

Aged↗