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Background: The risk for venous thromboembolism during pregnancy or postpartum is uncertain. Objectives: To estimate the relative and absolute risk for deep venous thrombosis and pulmonary embolism during pregnancy and postpartum and to describe trends in incidence. Design: Population-based inception cohort study using the resources of the Rochester Epidemiology Project. Setting: Olmsted County, Minnesota. Patients: Women with deep venous thrombosis or pulmonary embolism first diagnosed between 1966 and 1995, including women with venous thromboembolism during pregnancy or the postpartum period (defined as delivery of a newborn no more than 3 months before the deep venous thrombosis or pulmonary embolism event date, including delivery of a stillborn infant after the first trimester). Measurements: The authors obtained yearly counts of live births in Olmsted County between 1966 and 1995 from the Minnesota Department of Health. Results: The relative risk (standardized incidence ratio) for venous thromboembolism among pregnant or postpartum women was 4.29 (95% CI, 3.49 to 5.22; P< 0.001), and the overall incidence of venous thromboembolism (absolute risk) was 199.7 per 100000 woman-years. The annual incidence was 5 times higher among postpartum women than pregnant women (511.2 vs. 95.8 per 100 000), and the incidence of deep venous thrombosis was 3 times higher than that of pulmonary embolism (151.8 vs. 47.9 per 100 000). Pulmonary embolism was relatively uncommon during pregnancy versus the postpartum period (10.6 vs. 159.7 per 100 000). Over the 30-year study period, the incidence of venous thromboembolism during pregnancy remained relatively constant whereas the postpartum incidence of pulmonary embolism decreased more than 2-fold. Limitations: Because the Olmsted County population was 98% white and of non-Hispanic ethnicity, the results may not be generalizable to other ethnicities. Conclusions: Among pregnant women, the highest risk period for venous thromboembolism and pulmonary embolism in particular is during the postpartum period. Any prophylaxis against these events should be particularly targeted to postpartum women. Although the incidence of pulmonary embolism has decreased over time, the incidence of deep venous thrombosis remains unchanged, indicating the need to better identify pregnant women at increased risk.

Background: The introduction of routine measurement of serum calcium levels led to a sharp increase in the incidence of primary hyperparathyroidism in the early 1970s. Objective: To evaluate the trends in the incidence of primary hyperparathyroidism since the mid-1970s. Setting: Rochester and Olmsted County, Minnesota. Design: Population-based descriptive study. Patients: All residents of Rochester, Minnesota, who received an initial diagnosis of primary hyperparathyroidism between 1965 and 1992 were identified through the medical records linkage system of the Rochester Epidemiology Project: Included as persons having definite cases (92% of the total) were patients with pathologically confirmed hyperparathyroidism, hypercalcemia with inappropriately elevated parathyroid hormone levels, or hypercalcemia that had lasted for more than a year and had no cause other than primary hyperparathyroidism. Measurements: Incidence rates were calculated and directly standardized to the population structure of white persons in the United States in 1990. Results: From 1965 to June 1874 (the prescreening era), the age- and sex-adjusted incidence of primary hyperparathyroidism in Rochester was 15 cases per 100 000 person-years. After measurement of calcium levels was added to the automated serum chemistry panel in July 1974, the incidence increased to 112 per 100 000 person-years in 1975 and then decreased somewhat, reflecting a sweeping effect. Despite improved case ascertainment, however, the incidence rate has continued to decrease; in 1992, the incidence was 4 per 100 000 person-years. A few patients had complications that might have been caused by hyperparathyroidism (22% between 1965 and June 1974 and 6% thereafter), and survival was not impaired in either period. The maximum serum calcium levels did not change (P = 0.15). Conclusions: The progressive decrease in the incidence of primary hyperparathyroidism is unexpected and suggests a significant change in the epidemiology of this disease., The incidence of primary hyperparathyroidism in Rochester, Minnesota has declined dramatically ever since physicians began routinely measuring blood levels of calcium in all patients. Measurement of calcium levels began in 1974, after which the incidence of hyperparathyroidism jumped from 15 cases per 100,000 person-years to 112 cases per 100,000 person-years. However, the incidence soon began to decline and reached 4 cases per 100,000 person-years by 1992. There could be many reasons for this, including estrogen use, inadequate dietary calcium or ionizing radiation.

Osteoporosis, the loss of mass of mineralized bone, is the most common metabolic bone disease. The depletion of minerals reduces the strength of the bone, and creates a high risk of fracture, which is the only symptom of osteoporosis. It is estimated that 250,000 hip fractures, 250,000 wrist fractures, and 500,000 vertebral fractures can be attributed to osteoporosis in the United States each year. The national cost of osteoporosis is estimated at over $6 billion annually. Early detection and treatment of osteoporosis can reduce the incidence of these fractures. To determine whether a screening program might be effective, the medical literature on bone mass assessment was reviewed. Bone mass measurements may be accomplished by a number of different techniques, all of which involve radiation. Quantitative computed tomography may be used. Another method is single-photon absorptiometry, which calculates bone mass by measuring the absorption of gamma rays. This technique has been greatly improved by the introduction of dual-photon absorptiometry, which measures gamma absorption at two different wavelengths to achieve greater precision. Likewise, dual-energy X-ray techniques have now been introduced for the same reason. Prospective studies have clearly indicated that women with greater bone mass loss have a greater risk of fracture. Estimates suggest that a single bone mass scan at menopause might reduce the lifetime risk of hip fracture from 10 to 8 percent, a reduction of 20 percent. However, these numbers are based on many assumptions. Prophylactic treatment involves estrogen replacement therapy for decades, and it is uncertain what levels of patient compliance could be expected. There have been no studies on the efficacy of prophylactic treatment based on early bone mass measurements. The development and preliminary trial of a screening program will be necessary before the public health impact of such a program can be determined. Until such data are available, screening should be limited to women with other indication of osteoporosis, such as an abnormal X-rays. (Consumer Summary produced by Reliance Medical Information, Inc.)

The functional bowel disorders comprise gastrointestinal conditions attributable to no known structural abnormalities, or infectious or metabolic causes. Functional gastrointestinal symptoms are very common, affecting almost 4 million people between 1979 to 1981, and accounting for 427,000 hospitalizations in 1984. Because little is known about the underlying mechanisms of these disorders, diagnosis is often made by excluding other disorders. The development of standard criteria for diagnosing functional bowel disorders would improve diagnostic certainty, enhance physician and patient satisfaction, and standardize the selection of patients for clinical study. A questionnaire was recently developed that distinguishes persons with functional bowel disorders, such as non-ulcer dyspepsia and irritable bowel syndrome, from normal persons and patients with gastrointestinal disease of known cause. The questionnaire, which evaluated 46 symptom-related features, was completed by 361 subjects prior to clinical examination, which later indicated 115 cases of functional bowel disease, 101 cases of organic gastrointestinal disease, and 145 healthy persons. The newly-developed questionnaire may be a useful supplement in the diagnosis of functional gastrointestinal symptoms. (Consumer Summary produced by Reliance Medical Information, Inc.)

The identification of individuals at high risk for colon cancer is essential for an aggressive approach to preventing this disease. About six percent of the United States population will develop this common malignancy. Previous studies have suggested that individuals with pernicious anemia may be at increased risk for colon cancer but, thus far, reports have been inconclusive. Pernicious anemia is a serious blood condition characterized by a progressive decrease in red blood cells, muscle weakness, and gastrointestinal and neural disturbances; it can be successfully treated with vitamin B-12, iron and folic acid. A possible link between colon cancer and pernicious anemia is the high levels of gastrin (a digestive hormone) which often accompany pernicious anemia and may be associated with tumor growth. The complete medical history of 150 subjects who had pernicious anemia and lived in a particular city was reviewed retrospectively (the period covered was 1950 through 1979) and the incidence of cancers was recorded. These results were then compared with the expected rates of rectal and colon cancer in the local population. Among the patients with pernicious anemia, 14 cases of colorectal cancer were detected whereas 10.5 cases were expected. Individuals with pernicious anemia did not have a statistically significant increased risk for colorectal cancer. However, these patients may have a slightly higher than normal risk for colorectal adenocarcinoma (malignancy arising from glandular epithelium). The highest rates occurred in the five-year period after the initial diagnosis of pernicious anemia was made. During this period seven cancer cases occurred but only 1.7 were expected. No increased risk was observed for these individuals prior to or shortly after diagnosis of pernicious anemia. (Consumer Summary produced by Reliance Medical Information, Inc.)

Fluoride has been proposed as a treatment for vertebral crush fracture syndrome, based on observations that fluoride intoxication is associated with increased mass of the skeleton and bony overgrowth. Fluoride increases bone density by increasing bone formation, and has more effect on the axial skeleton, specifically the spine, than the appendicular skeleton, which consists of the shoulders, the upper and lower extremities, and the pelvis. In one study, the fracture rate in patients receiving fluoride was 39 percent, while it was 50 percent in patients receiving other therapies. Fluoride therapy for vertebral crush syndrome is widely used and has been formally approved in eight European countries. It has not been associated with adverse consequences over a period of 20 years of clinical experience, and alternative treatments for vertebral crush syndrome have not been shown to be as effective. Currently, fluoride therapy is recommended for treating vertebral osteoporosis, a decrease in bone mass, in adults with symptoms of crush fracture syndrome, and should be supplemented with calcium and vitamin D. Fluoride should not be used in conditions of impaired kidney function, pregnancy, peptic ulcers, osteomalacia (a bone softening disease), and previous hip fracture. Effects of fluoride should be monitored by measuring bone mass each year. Adverse effects include nausea, vomiting, mild gastrointestinal bleeding, lower extremity pain, and possible hip fracture. (Consumer Summary produced by Reliance Medical Information, Inc.)