Longitudinal Association of Sleep-Disordered Breathing and Nondipping of Nocturnal Blood Pressure in the Wisconsin Sleep Cohort Study

Study objectives: The association of sleep-disordered breathing (SDB) and blunting of normal nocturnal lowering of blood pressure (BP) (nondipping) has only been examined cross-sectionally. The purpose of this study is to investigate whether SDB is prospectively associated with nondipping. Methods: The longitudinal association between SDB and incident nondipping was examined in a subsample of 328 adults enrolled in the Wisconsin Sleep Cohort Study who completed 2 or more 24-hour ambulatory BP studies over an average of 7.2 years of follow-up. SDB identified by baseline in-laboratory polysomnography was defined by apnea-hypopnea index (AHI) categories. Systolic and diastolic nondipping was defined by systolic and diastolic sleep-wake BP ratios \u3e 0.9. All models were adjusted for age, sex, body mass index at baseline and follow-up, smoking, alcohol consumption, hypertension, sleep time, length of follow-up time, and antihypertensive medication use. Results: There was a dose-response increased odds of developing systolic nondipping in participants with SDB. The adjusted odds ratios (95% confidence interval) of incident systolic nondipping for baseline AHI 5 to \u3c 15 and AHI ≥ 15, versus AHI Conclusions: Our longitudinal findings of a dose-response increase in development of systolic nondipping of BP with severity of SDB at baseline in a population-based sample provide evidence consistent with a causal link. Nocturnal systolic nondipping may be a mechanism by which SDB contributes to increased cardiovascular disease

Obstructive sleep apnoea during REM sleep and incident non-dipping of nocturnal blood pressure: a longitudinal analysis of the Wisconsin Sleep Cohort

Background Non-dipping of nocturnal blood pressure (BP) is associated with target organ damage and cardiovascular disease. Obstructive sleep apnoea (OSA) is associated with incident non-dipping. However, the relationship between disordered breathing during rapid eye movement (REM) sleep and the risk of developing non-dipping has not been examined. This study investigates whether OSA during REM sleep is associated with incident non-dipping. Methods Our sample included 269 adults enrolled in the Wisconsin Sleep Cohort Study who completed two or more 24 h ambulatory BP studies over an average of 6.6 years of follow-up. After excluding participants with prevalent non-dipping BP or antihypertensive use at baseline, there were 199 and 215 participants available for longitudinal analysis of systolic and diastolic non-dipping, respectively. OSA in REM and non-REM sleep were defined by apnoea hypopnoea index (AHI) from baseline in-laboratory polysomnograms. Systolic and diastolic non-dipping were defined by systolic and diastolic sleep/wake BP ratios \u3e0.9. Modified Poisson regression models estimated the relative risks for the relationship between REM AHI and incident non-dipping, adjusting for non-REM AHI and other covariates. Results There was a dose–response greater risk of developing systolic and diastolic non-dipping BP with greater severity of OSA in REM sleep (p-trend=0.021 for systolic and 0.024 for diastolic non-dipping). Relative to those with REM AHI\u3c1 event/h, those with REM AHI≥15 had higher relative risk of incident systolic non-dipping (2.84, 95% CI 1.10 to 7.29) and incident diastolic non-dipping (4.27, 95% CI 1.20 to 15.13). Conclusions Our findings indicate that in a population-based sample, REM OSA is independently associated with incident non-dipping of BP

Slow-Release Oxprenolol Compared with Oxprenolol in Hypertensive Patients: A Multicenter Clinical Trial

Oxprenolol (OX) is a nonselective, β-adrenergic blocking agent with intrinsic sympathomimetic activity. We studied 178 patients in five centers to determine whether a polymer-matrix-based, slow-release preparation of oxprenolol (SR-OX) given once daily was as effective as the standard preparation given twice daily for the treatment of patients with mild to moderate hypertension. After a placebo washout phase, patients were treated with OX until blood pressure was controlled. They were then randomized in a double-blind fashion to continue the same dose, given as either OX bid or SR-OX qd with a placebo as the second dose. All patients took hydrochlorothiazide 50–100 mg/d throughout the study. Blood pressure was reduced 23/15 mm Hg (p < 0.001) and pulse 8 beats/min in the SR-OX group (n = 67) and 24/17 mm Hg (p < 0.001) and 8 beats/min in the OX group (n = 72) by titrating standard OX. After randomization to SR-OX or OX, there were no further changes over six weeks. Home-determined blood pressures showed no loss of control in the evening. There were no unexpected adverse effects. We conclude that SR-OX given once daily is as effective as OX given twice daily for the treatment of hypertension

Efficacy of Patient Letter Reminders on Cervical Cancer Screening: A Meta-analysis

OBJECTIVE: To perform a meta-analysis on existing randomized controlled trials to investigate the efficacy of patient letter reminders on increasing cervical cancer screening using Pap smears. METHODS: A search was conducted for all relevant published and unpublished studies between the years 1966 and 2000. Eligibility criteria included randomized controlled studies that examined populations due for Pap smear screening. The intervention studied was in the form of a reminder letter. The Mantel-Haenszel method was used to measure the summary effect of the intervention. A test for homogeneity using the Mantel-Haenszel method was performed. RESULTS: Ten articles fulfilled the inclusion criteria, including one unpublished study. The test for homogeneity showed evidence of heterogeneity (χ2 = 31, 9 df, P < .001). An analysis for causes of heterogeneity was pursued. Division into subpopulations based on socioeconomic status resolved the heterogeneity (χ2 = 5.2, 8 df, P = .75). The studies evaluating those in lower socioeconomic groups had a smaller response (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.99 to 1.35) than those studies using mixed populations (OR, 2.02; 95% CI, 1.79 to 2.28). The pooled odds ratio showed that patients who received the intervention were significantly more likely to return for screening than those who did not (OR, 1.64; 95% CI, 1.49 to 1.80). CONCLUSIONS: Patient reminders in the form of mailed letters increase the rate of cervical cancer screening. Patient letter reminders have less efficacy in lower socioeconomic groups

Cigarette Smoking Interferes With Treatment of Hypertension

• We retrospectively analyzed two studies to determine whether smoking affected the treatment of hypertension. In a study of the effects of propranolol hydrochloride (a hepatically metabolized β-blocker) vs hydrochlorothiazide, 108 smokers and 232 nonsmokers were randomized to the propranolol treatment group. The propranolol-treated smokers tended to be younger, taller, thinner, and were more likely to be black. This group also had an initial blood pressure reduction (± SD) of -7.9 ± 12.9/ -8.7 ± 8.4 mm Hg compared with -10.7 ± 13.0/ -10.9 ± 7.1 mm Hg for the nonsmokers. Blood pressure increased less during the one-year maintenance period for the nonsmokers. However, when analyzed by race, this effect was seen in blacks, but not in whites. Diastolic blood pressure tended to be reduced more in nonsmokers (vs smokers) receiving hydrochlorothiazide (-12.1 ± 6.7 vs -10.7 ± 6.7 mm Hg, respectively). The second study compared the effects of nadolol (a renally excreted β-blocker) with bendroflumethiazide. There were no significant effects on blood pressure for either of these drugs. In both studies, there was a greater tendency for smokers to be terminated from the study irrespective of drug group. We conclude that cigarette smoking does interfere with the treatment of hypertension in general, and especially with reduction of blood pressure by propranolol in black patients.(Arch Intern Med 1988;148:2116-2119