Methodologic limitations in the calculation of incidence rates for hypertension and in the assessment of associations between rates of change in attributes and the development of hypertension were ...examined for Pittsburgh's MRFIT Usual Care population. In a group of normotensive middle-aged men at high risk for the development of coronary heart disease, the incidence of hypertension ranged from 6.2 to 15.5 per 100 man years, depending on the definition of hypertension. A simulation study showed that the magnitude of these incidence rates could be explained by random variation in the measurement of blood pressure. Controlling for these random effects, the development of hypertension was associated with high normal baseline diastolic blood pressure and with a reported past diagnosis of hypertension, but not with age or baseline body mass index. Finally, a method, estimating the relative risk associating weight gain and the development of hypertension, was presented.
BACKGROUND Control of high blood pressure (BP) in older adults is an important part of public health efforts at prevention. OBJECTIVE To assess recent time trends in the awareness, treatment, and ...control of high BP and in the use of medications to treat high BP. METHODS In the Cardiovascular Health Study, 5888 adults 65 years and older were recruited from 4 US centers. At baseline, participants underwent an extensive examination that included the measurement of BP, use of medications, and other risk factors. Participants were followed up with annual visits that assessed BP and medication use from baseline in 1989-1990 through the examination in 1998-1999. The primary outcome measures were control of BP to levels lower than than 140/90 mm Hg and the prevalence of use of various classes of antihypertensive medications. RESULTS The awareness, treatment, and control of high BP improved during the 1990s. The proportions aware and treated were higher among blacks than whites, though control prevalences were similar. For both groups combined, the control of high BP to lower than 140/90 mm Hg increased from 37% at baseline to 49% in 1999. The 51% whose BP was not controlled generally had isolated mild to moderate elevations in systolic BP. Among treated persons, the improvement in control was achieved in part by a mean increase of 0.2 antihypertensive medications per person over the course of 9 years. Improved control was also achieved by increasing the proportion of the entire Cardiovascular Health Study population that was treated for hypertension, from 34.5% in 1990 to 51.1% in 1999. Time trends in antihypertensive drug use were pronounced. Among those without coronary disease, the use of low-dose diuretics and β-blockers decreased, while the use of newer agents, such as calcium channel blockers, angiotensin-converting enzyme inhibitors, and α-blockers increased. CONCLUSIONS While control of high BP improved in the 1990s, about half the participants with hypertension had uncontrolled BP, primarily mild to moderate elevations in systolic BP. Low-dose diuretics and β-blockers—the preferred agents since 1993 according to the recommendations of the Joint National Committee on the Detection, Evaluation and Treatment of High Blood Pressure—remained underused. More widespread use of these agents will be an important intervention to prevent the devastating complications of hypertension, including stroke, myocardial infarction, and heart failure.Arch Intern Med. 2002;162(20):2325-2332-->
Mutations of the p53 tumor suppressor gene are the most common genetic alterations associated with human cancer. Tumor-associated
p53 mutations often show characteristic tissue-specific profiles ...which may infer environmentally induced mutational mechanisms.
The p53 mutational frequency and spectrum were determined for 95 carcinomas of the upper and lower respiratory tract (32 lung
and 63 upper respiratory tract). Mutations were identified at a frequency of 30% in upper respiratory tract (URT) tumors and
31% in lung tumors. All 29 identified mutations were single-base substitutions. Comparison of the frequency of specific base
substitutions between lung and URT showed a striking difference. Transitions occurred at a frequency of 68% in URT, but only
30% in lung. Mutations involving G:C-->A:T transitions, which are commonly reported in gastric and esophageal tumors, were
the most frequently identified alteration in URT (11/19). Mutations involving G:C-->T:A transversions, which were relatively
common in lung tumors (3/10) and are representative of tobacco smoke-induced mutations were rare in URT tumors (1/19). Interestingly,
G:C-->A:T mutations at CpG sites, which are characteristic of endogenous processes, were observed frequently in URT tumors
(9/19) but only rarely in lung tumors (1/10), suggesting that both endogenous and exogenous factors are responsible for the
observed differences in mutational spectra between the upper and lower respiratory systems.
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