Lifestyle changes and blood pressure control: a community-based cross-sectional survey (2006 Ontario Survey on the Prevalence and Control of Hypertension).

To evaluate lifestyle changes and their impact on hypertension control in a sample of hypertensive respondents in Ontario, Canada, diet, physical activity, and other nonpharmacologic measures were recorded using a structured questionnaire during the 2006 Ontario Survey on the Prevalence and Control of Hypertension. Responses were weighted to the total adult population of 7,996,653 in Ontario. The prevalence of hypertension was 21%; 42% of hypertensive persons received therapy with antihypertensive drugs and lifestyle changes, and 41% received therapy with drugs only. Blood pressure was controlled in 85% of respondents who used only drugs and in 78% of those who stated that they received therapy with combined drug treatment and lifestyle changes. Fewer than half of hypertensive respondents practiced lifestyle changes (in combination with drug treatment) for blood pressure control. Lifestyle measures in addition to medication use did not result in better control of hypertension compared to only medication use.

Comparison between an automated and manual sphygmomanometer in a population survey.

BACKGROUND: An automated sphygmomanometer, the BpTRU, was used in a blood pressure (BP) survey of 2,551 residents in the province of Ontario. Automated BP readings were compared with measurements taken by a mercury sphygmomanometer under standardized conditions in a random 10% sample. METHODS: BP was recorded in 238 individuals in random order using both a standard mercury device and an automated BP recorder, the BpTRU. All subjects rested for 5 min prior to the first BP reading, which was then discarded. The mean of the next three readings was obtained using the mercury device whereas the BpTRU was set to record a mean of five readings taken at 1 min intervals with subjects resting alone in a quiet room. RESULTS: The mean s.d. BP with the automated device was 115 +/- 16/71 +/- 10 mm Hg compared to 118 +/- 16/74 +/- 10 mm Hg for the manual BP (P < 0.001). A systolic BP > or = 140 mm Hg was present for 16 automated and 19 manual readings. Similarly, the diastolic BP was > or = 90 mm Hg for 9 automated and 14 manual readings. Linear regression analysis showed that automated BP was a significant (P < 0.001) predictor of both manual systolic and diastolic BP. CONCLUSION: Conventional manual BP readings can be replaced by readings taken using a validated, automated BP recorder in population surveys. The slightly lower readings obtained with the BpTRU device (in the context of reduced observer-subject interaction) may be a more accurate estimate of BP status.

Results of the Ontario survey on the prevalence and control of hypertension.

BACKGROUND: Available information on the prevalence and management of hypertension in the Canadian population dates back to 1986-1992 and probably does not reflect the current status of this major risk factor for cardiovascular disease. We sought to evaluate the current prevalence and management of hypertension among adults in the province of Ontario. METHODS: Potential respondents from randomly selected dwellings within target neighbourhoods in 16 municipalities were contacted at their homes to request participation in the study. For potential respondents who agreed to participate, blood pressure was measured with an automated device. Estimation weights were used to obtain representative estimates of population parameters. Responses were weighted to the total adult population in Ontario of 7,996,653. RESULTS: From 6436 eligible dwellings, contact was made with 4559 potential participants, of whom 2992 agreed to participate. Blood pressure measurements were obtained for 2551 of these respondents (age 20-79 years). Hypertension, defined as systolic blood pressure of 140 mm Hg or more, diastolic blood pressure of 90 mm Hg or more, or treatment with an antihypertensive medication, was identified in 21.3% of the population overall (23.8% of men and 19.0% of women). Prevalence increased with age, from 3.4% among participants 20-39 years of age to 51.6% among those 60-79 years of age. Hypertension was more common among black people and people of South Asian background than among white people; hypertension was also associated with higher body mass index. Among participants with hypertension, 65.7% were undergoing treatment with control of hypertension, 14.7% were undergoing treatment but the hypertension was not controlled, and 19.5% were not receiving any treatment (including 13.7% who were unaware of their hypertension). The extent of control of hypertension did not differ significantly by age, sex, ethnic background or comorbidities. INTERPRETATION: In Ontario, the overall prevalence of hypertension is high in the older population but appears not to have increased in recent decades. Hypertension management has improved markedly among all age groups and for both sexes.

Postexercise heat loss and hemodynamic responses during head-down tilt are similar between genders.

PURPOSE: We evaluated the hypothesis that during recovery from dynamic exercise in the 15 degrees head-down tilt (HDT) position, the attenuation of the fall in mean arterial pressure (MAP), cutaneous vascular conductance (CVC), and sweat rate, and the augmentation of the rate of esophageal temperature (T(es)) decay relative to the upright seated (URS) posture, would be different between males and females. METHODS: Fourteen subjects (seven males, seven females) performed two experimental protocols: 1) 15 min of cycle ergometry at 75% VO2peak and then 60 min of recovery in the URS posture; or 2) 15 min of cycle ergometry at 75% VO2peak and then 60 min of recovery in the 15 degrees HDT position. Mean skin temperature, Tes, CVC, sweat rate, cardiac output (CO), stroke volume (SV), heart rate (HR), total peripheral resistance (TPR), and MAP were recorded at baseline; end of exercise; 2 min, 5 min, 8 min, 12 min, 15 min, and 20 min after exercise; and every 5 min until the end of recovery (60 min). RESULTS: During recovery from exercise, we observed significantly greater values for MAP, CVC, and sweat rate with HDT in comparison with the URS recovery posture (P

15 degrees head-down tilt attenuates the postexercise reduction in cutaneous vascular conductance and sweating and decreases esophageal temperature recovery time.

The following study examined the effect of 15 degrees head-down tilt (HDT) on postexercise heat loss and hemodynamic responses. We tested the hypothesis that recovery from dynamic exercise in the HDT position would attenuate the reduction in the heat loss responses of cutaneous vascular conductance (CVC) and sweating relative to upright seated (URS) recovery in association with an augmented hemodynamic response and an increased rate of core temperature decay. Seven male subjects performed the following three experimental protocols: 1) 60 min in the URS posture followed by 60 min in the 15 degrees HDT position; 2) 15 min of cycle ergometry at 75% of their predetermined V(O2 peak) followed by 60 min of recovery in the URS posture; or 3) 15 min of cycle ergometry at 75% of their predetermined V(O2 peak) followed by 60 min of recovery in the 15 degrees HDT position. Mean skin temperature, esophageal temperature (T(es)), skin blood flow, sweat rate, cardiac output (CO), stroke volume (SV), heart rate (HR), total peripheral resistance, and mean arterial pressure (MAP) were recorded at baseline, end exercise, 2, 5, 8, 12, 15, and 20 min, and every 5 min until end of recovery (60 min). Without preceding exercise, HDT decreased HR and increased SV (P < or = 0.05). During recovery after exercise, a significantly greater MAP, SV, CVC, and sweat rate and a significantly lower HR were found with HDT compared with URS posture (P < or = 0.05). Subsequently, a significantly lower T(es) was observed with HDT after 15 min of recovery onward (P < or = 0.05). At the end of 60 min of recovery, T(es) remained significantly elevated above baseline with URS (P < or = 0.05); however, T(es) returned to baseline with HDT. In conclusion, extended recovery from dynamic exercise in the 15 degrees HDT position attenuates the reduction in CVC and sweating, thereby significantly increasing the rate of T(es) decay compared with recovery in the URS posture.

Nonthermoregulatory control of cutaneous vascular conductance and sweating during recovery from dynamic exercise in women.

The purpose of the study was to examine the effect of 1) active (loadless pedaling), 2) passive (assisted pedaling), and 3) inactive (motionless) recovery modes on mean arterial pressure (MAP), cutaneous vascular conductance (CVC), and sweat rate during recovery after 15 min of dynamic exercise in women. It was hypothesized that an active recovery mode would be most effective in attenuating the fall in MAP, CVC, and sweating during exercise recovery. Ten female subjects performed 15 min of cycle ergometer exercise at 70% of their predetermined peak oxygen consumption followed by 20 min of 1) active, 2) passive, or 3) inactive recovery. Mean skin temperature (Tsk), esophageal temperature (Tes), skin blood flow, sweating, cardiac output (CO), stroke volume (SV), heart rate (HR), total peripheral resistance (TPR), and MAP were recorded at baseline, end exercise, and 2, 5, 8, 12, 15, and 20 min postexercise. Cutaneous vascular conductance (CVC) was calculated as the ratio of laser-Doppler blood flow to MAP. In the active recovery mode, CVC, sweat rate, MAP, CO, and SV remained elevated over inactive values (P < 0.05). The passive mode was equally as effective as the active mode in maintaining MAP. Sweat rate was different among all modes after 12 min of recovery (P < 0.05). TPR during active recovery remained significantly lower than during recovery in the inactive mode (P < 0.05). No differences in either Tes or Tsk were observed among conditions. The results indicate that CVC can be modulated by central command and possibly cardiopulmonary baroreceptors in women. However, differences in sweat rate may be influenced by factors such as central command, mechanoreceptor stimulation, or cardiopulmonary baroreceptors.

Obesity and the prevalence and management of hypertension in Ontario, Canada.

BACKGROUND: We evaluated the association of body weight with the prevalence of hypertension by age and sex, as well as the treatment and control rates in obese and nonobese hypertensives among adults in the province of Ontario, Canada. METHODS: Cross-sectional, population-based survey of 2,510 adults, 20-79 years of age representative of the Ontario population of 7,996,653. Height, weight, arm and waist circumference, and blood pressure (BP) were directly measured by a trained nurse. RESULTS: Prevalence of obesity (body mass index (BMI) > or =30) increased from 16% in the 20-39 years age-group to 33% in the 60-79 years age group, similarly in men and women. Prevalence of hypertension increased as BMI and age increased: in the older age group (60+) from 36% in the lean to 51% for the overweight, 59% in the obese stage I, and 68% in the obese stage II/III. Prevalence of self-reported diabetes followed a similar pattern. Presence of other risk factors (diabetes and dyslipidemia) was independently associated with higher hypertension rates. Treatment and control rates of hypertension varied by BMI and gender. Lean hypertensive males had the lowest control rates (42%) and the highest systolic BPs compared to overweight (79%) and obese (64%) males. This difference was not apparent in females. CONCLUSIONS: Obesity is associated with markedly higher prevalence of hypertension and diabetes with age. If obesity per se is indeed a contributing factor, public health strategies to reduce the obesity epidemic would also markedly reduce the burden of hypertension and diabetes.

Antihypertensive medication use and blood pressure control: a community-based cross-sectional survey (ON-BP).

BACKGROUND: The Ontario Blood Pressure (ON-BP) survey reported high treatment and control rates for hypertension in the province of Ontario, Canada, in a survey performed in 2006. This study examined patterns of utilization of antihypertensive drug classes and their impact on blood pressure (BP) control. METHODS: Cross-sectional, population-based survey of adults, 20-79 years of age (population 7,996,653). Responses are weighted to the Ontario hypertensive population of 1,498,045. RESULTS: Of all hypertensives, 51 and 49% were on monotherapy vs. 2+ drug therapy with similar control rates (86 vs. 80%, respectively). In those on monotherapy a renin-angiotensin system (RAS) blocker was the most commonly used drug class (62%) and use of other drug classes was only approximately 10%. In those on 2+ therapy, a RAS blocker was also the most common class (80%), followed by a diuretic (67%). In diabetics with hypertension 46 and 54% were on monotherapy vs. 2+ drug therapy with significantly higher control rates on monotherapy (90 vs. 46%). RAS blocker was also the most common drug class (85 and 80%, respectively), but in those on 2+ drugs only 45% were on a diuretic. Control rates did not differ by type of drug treatment in the overall hypertensive population and those with a comorbidity, but were low in diabetics on 2+ therapy and particularly in those on a calcium channel blocker (CCB) or diuretic. CONCLUSIONS: High treatment and control rates of hypertension in Ontario are associated with high utilization of RAS blockers. Diabetics on 2+ therapy are the least effectively controlled, possibly reflecting the limited use of diuretics.

Can supine recovery mitigate the exercise intensity dependent attenuation of post-exercise heat loss responses?

Cutaneous vascular conductance (CVC) and sweat rate are subject to non-thermal baroreflex-mediated attenuation post-exercise. Various recovery modalities have been effective in attenuating these decreases in CVC and sweat rate post-exercise. However, the interaction of recovery posture and preceding exercise intensity on post-exercise thermoregulation remains unresolved. We evaluated the combined effect of supine recovery and exercise intensity on post-exercise cardiovascular and thermal responses relative to an upright seated posture. Seven females performed 15 min of cycling ergometry at low- (LIE, 55% maximal oxygen consumption) or high-(HIE, 85% maximal oxygen consumption) intensity followed by 60 min of recovery in either an upright seated or supine posture. Esophageal temperature, CVC, sweat rate, cardiac output, stroke volume, heart rate, total peripheral resistance, and mean arterial pressure (MAP) were measured at baseline, at end-exercise, and at 2, 5, 12, 20, and every 10 min thereafter until the end of recovery. MAP and stroke volume were maintained during supine recovery to a greater extent relative to an upright seated recovery following HIE (p