Leonard T. Kurland

Polymyalgia Rheumatica: A 10-Year Epidemiologic and Clinical Study

Ninety-six patients with polymyalgia rheumatica were identified in Olmsted County, Minnesota, during the 10-year period 1970 to 1979. Giant cell arteritis was found in 15 of the 96 patients. The average annual incidence of polymyalgia rheumatica in the population increased from 19.8 per 100 000 in persons 50 to 59 years of age, to a maximum of 112.2 per 100 000 in persons 70 to 79 years of age. Eighty-three of the 96 patients (86%) had recovered by the end of the study. Median duration of the disease was 11 months (range, 2 to 54 months). Polymyalgia rheumatica had no effect on survival. Both corticosteroids and nonsteroidal anti-inflammatory drugs were used in treatment. Response was more rapid in patients given corticosteroids, but nonsteroidal drugs were used successfully, especially in milder cases. Relapses and adverse reactions to treatment were more frequent in patients given corticosteroids. The findings show that polymyalgia rheumatica is a relatively common disease in middle-aged and older persons and generally runs a self-limited course.

Alzheimer's Disease and Cumulative Exposure to Anesthesia: A Case-Control Study

Objective: To evaluate prior exposure to general anesthesia as a potential risk factor for Alzheimers disease (AD).

Anorexia Nervosa in Rochester, Minnesota: A 45-Year Study

The incidence of anorexia nervosa during a 45-year period (1935 through 1979) was determined for the population of Rochester, Minnesota, from the epidemiology archives at the Mayo Clinic. The medical records of local residents with the diagnosis of anorexia nervosa were the primary source for case ascertainment, although records of those whose diagnoses might have been shielding anorexia nervosa were also screened. Standard criteria for diagnosis were applied. We identified 140 (128 female and 12 male) residents of the community who fulfilled the diagnostic criteria for anorexia nervosa. No significant long-term trend in rates was ascertained. The overall age- and sex-adjusted incidence rate was 7.3 per 100,000 person-years. The highest age-specific incidence rate (56.7 per 100,000 person-years) occurred in female residents 15 to 19 years old. The prevalence rate on Jan. 1, 1980, for Rochester residents with a history of the disease, age- and sex-adjusted to the 1970 US white population, was 113.1 per 100,000 (203.9 for female and 16.9 for male residents).

Cancer After Exposure to Metronidazole

We assessed the risk of occurrence of cancer associated with exposure to metronidazole in the 771 female residents of Rochester, Minnesota, who were treated with metronidazole for vaginal trichomoniasis during the period 1960 through 1969 and were followed up for a total of 12,628 person-years. Standardized morbidity and mortality ratios were determined by using an expected number calculated by applying age-specific incidence rates from Rochester studies and Cancer Surveillance, Epidemiology, and End-Results Reporting (SEER) data to the person-years of follow-up. The overall standardized morbidity ratios for cancer at all sites were 1.4 (Rochester, 1978 through 1983), 1.5 (SEER data for Iowa, 1978 through 1981), and 1.2 (SEER data for Connecticut, 1978 through 1981). By site of the cancers, the standardized morbidity ratios greater than unity were those for malignant lesions of the lung, breast, thyroid, bladder, brain, kidney, nasopharynx, and oral cavity, as well as for multiple myeloma and malignant melanoma; however, the only significantly elevated standardized morbidity ratio was that for bronchogenic carcinoma. After adjustment for smoking status, the standardized morbidity ratio for bronchogenic cancer was 2.5 (95% confidence interval of 1.3 to 4.4). The standardized mortality ratio for cancer at all sites was 1.4 (95% confidence interval of 0.9 to 2.2). The analysis of these data suggests no significant increase in cancer-related morbidity or mortality for women exposed to metronidazole for treatment of vaginal trichomoniasis.

Pityriasis rosea in Rochester, Minnesota, 1969 to 1978

A population-based epidemiologic study of pityriasis rosea was developed for Rochester, MN, for a recent 10-year period. Nine hundred thirty-nine patients with pityriasis rosea (340 male patients and 599 female patients) who resided within Rochester city limits at the time the diagnosis was made were included. The average annual incidence rate of this disease was 172.2 per 100,000 person-years (158.9 per 100,000, adjusted to the 1970 U.S. white population). Female patients predominated by a margin of 1.5:1.0. More than 75% of the patients were between the ages of 10 and 35 years, with a mean age of 22.7 years and a range of 10 months to 78 years. There was a recurrence of the illness in 1.8% of the patients after an average of 4.5 years of follow-up. The highest rate was noted in 1972, following which there was a steady and significant decline in incidence. The incidence of the disease was significantly higher in the colder months than in the warmer season. Patients in twenty-one close-contact pairs experienced the disease at varying intervals. Recent past infections or history of atopy was noted in nearly one third of the cases.

Malignant Potential of the Cryptorchid Testis

A follow-up study of 224 male patients from Rochester, Minnesota, diagnosed with cryptorchidism during the period from 1935 through 1974 was conducted to assess the frequency of subsequent testicular neoplasms. Age-specific rates for testicular neoplasm in this community were used to estimate an expected number for comparison with that observed. Two malignant testicular neoplasms have occurred in this cohort; thus, the standardized morbidity ratio was 11.4 (95% confidence interval, 1.4 to 41.1). Of the 158 patients born in the community, 11% were known to have birth weights of less than 2,500 g, approximately twice the expected occurrence. Increased risks were also noted for inguinal hernia, hypospadias, Downs syndrome, cleft lip or palate (or both), clubfoot, and congenital heart disease, for which the standardized morbidity ratios were 3.6, 4.7, 17.8, 11.3, 11.7, and 2.7, respectively. The increased risk for malignant neoplasms observed in this cohort of patients with cryptorchidism is consistent with that found in earlier studies.

Update on the Epidemiology of Multiple Sclerosis

Neuroepidemiology has been important in providing clues about the cause and pathogenesis of multiple sclerosis. In this review, we update the incidence and prevalence rates of multiple sclerosis in Olmsted County, Minnesota, and examine the potential role of viruses, exposure to animals, toxins, trauma, and diet in the development of this disease. Diseases of probable autoimmune nature have also been linked to multiple sclerosis. These descriptive data may contribute to the formulation of testable specific hypotheses about the pathogenesis and treatment of multiple sclerosis and other demyelinating diseases.

Cutaneous Malignant Melanoma in Rochester, Minnesota: Trends in Incidence and Survivorship, 1950 Through 1985

In Rochester, Minnesota, 107 incidence cases of cutaneous malignant melanoma (in 46 male and 61 female patients) were diagnosed during the years 1950 through 1985. Overall crude incidence rates were 6.0 and 6.6 per 100,000 males and females, respectively. Evaluation of trends in 9-year periods showed that the rates increased from 3.2 to 8.9 for males (P = 0.015) and from 4.4 to 11.7 for females (P less than 0.001). Age-specific rates suggested that the highest incidence occurs in the age-groups 50 to 59 years and 70 years or older for males and 40 to 49 years and 70 years or older for females. Lesions were most common in the head and neck area among males (P = 0.044) and on the lower extremities among females (P = 0.018). The most frequent histologic type was superficial spreading melanoma (61%). Five-year survival was diminished overall for patients with cutaneous malignant melanoma--0.72 in comparison with 0.88 expected for the general population. Statistically significant risk factors for survival were depth of invasion of the lesion (Clark level), thickness of the lesion, histologic type, and age of the patient.

An Anatomy of the Autopsy, Olmsted County, 1935 Through 1985

In this study, we examined in detail the patterns of autopsy rates for a half century (1935 through 1985) among residents of Olmsted County, Minnesota. The time trend of the autopsy in this community represents, in many respects, a microcosm of national trends. In the process of this analysis, we identified several medical and socioeconomic variables that may influence the rate of autopsy, including the age at death, physical location of death, gender, surgical procedures preceding death, immediate cause of death, and direct and indirect costs of the autopsy. In particular, the advancing mean age at death and the increase of the nursing home as a social phenomenon seem to have had a profound effect on autopsy rates both in Olmsted County and throughout the United States.

Malignant lymphoma in Olmsted County, Minnesota, 1970 through 1977

A study of the incidence of malignant lymphoma in Olmsted County, Minnesota, revealed 91 new cases during the period 1970 through 1977. On the basis of the analyzed data, the overall average annual incidence rate per 100,000 population was 12.2 for males and 14.2 for females. The rates for both sexes combined (unadjusted for age) were 1.5 for Hodgkins disease, 6.2 for lymphosarcoma, and 5.5 for reticulum cell sarcoma. The incidence rate for Hodgkins disease decreased insignificantly, whereas that for both lymphosarcoma and reticulum cell sarcoma increased significantly during the period 1970 through 1977 in comparison with rates from the period 1945 through 1969. The largest increase was for rural males, for whom the rates for all three histologic types of lymphoma were substantially higher than those for urban males.