Relationship Among Morning Blood Pressure Surge, 24-Hour Blood Pressure Variability, and Cardiovascular Outcomes in a White Population

Cardiovascular events have their greatest prevalence in the early morning period. Whether this is attributable to an arousal-dependent blood pressure (BP) increase is far from being clear. It is also not clear to what extent this phenomenon reflects overall 24-hour BP variability. In 2051 subjects (aged 25–74 years) representative of the population of Monza (Italy), we measured 24-hour ambulatory systolic BP (SBP) and calculated the difference between the 2-hour average values after morning arousal and the lowest 3 or average 2-hour values before arousal (morning BP surge 1 and 2, respectively). For either measure, we sought the relationship with a variety of indices of 24-hour SBP variability and collected information on (1) the occurrence of cardiovascular and all cause deaths during a follow-up of ≈16 years and (2) the appearance of echocardiographic left ventricular hypertrophy after 10 years from the baseline visit. Morning SBP surge 1 was directly related to indices of 24-hour SBP variability, including those made independent on the magnitude of the day–night SBP difference. There was a weak positive relationship between morning SBP surge 1 and the risk of cardiovascular and all-cause death, which disappeared after adjustment for confounders. This was the case also for development of left ventricular hypertrophy. Morning SBP surge 2 was smaller, inconsistently related to 24-hour SBP variability and not at all related to fatal events or new-onset left ventricular hypertrophy. In a white population, morning BP surge was not found to be an independent predictor of cardiovascular death, all-cause death, or development of high cardiovascular risk (as documented by new-onset cardiac damage) even when appropriately assessed by measures that reflect its association with 24-hour BP variability.

Impact of body mass index and waist circumference on the cardiovascular risk and all-cause death in a general population: data from the PAMELA study

BACKGROUND AND AIMS

Elevated values of body mass index (BMI) and waist circumference (WC) are associated with an augmented cardiovascular (CV) risk. It is debated, however, whether and to what extent this depends on the body fat increase 'per se' or on the related cardiometabolic alterations.

METHODS AND RESULTS

In 2005 subjects randomly selected from the general population of Monza (Italy), we assessed BMI, WC, office, home and 24 h blood pressure (BP), heart rate and metabolic variables. The impact of BMI and WC on the incidence of CV events, CV and all-cause mortality was estimated during a 148-month follow-up. Progressively higher values of BMI and WC were associated with a progressive increase in office, home and 24 h BP and in erratic BP variability (P < 0.0001 for trend). Metabolic variables were directly and significantly (P < 0.0001) related to BMI and WC, while an inverse significant relationship was detected with high-density lipoprotein (HDL)-cholesterol. The incidence of CV events, CV and all-cause deaths increased progressively from the lowest to the highest quintile of BMI and WC (P for trend always <0.005). Baseline BMI and WC higher by respectively 1 kg m⁻² and 1 cm were associated with an increased risk of CV events, CV and all-cause death by 8%, 12% and 7% (for baseline BMI) and 4%, 5% and 4% (for baseline WC), respectively. After adjustment for confounders, only the increased risk of CV death related to higher baseline BMI remained significant (hazard ratio (HR) 1.062, confidence interval (CI) 95% 1.003-1.126, P < 0.05).

CONCLUSION

The adverse prognostic impact of the accumulation of body fat is mediated by the associated haemodynamic and metabolic alterations. Baseline values of BMI, however, are an independent predictor of CV mortality.

Impact of Body Mass Index and Waist Circumference on the Long-Term Risk of Diabetes Mellitus, Hypertension, and Cardiac Organ Damage

Obesity is associated with a higher risk of developing diabetes mellitus (DM), hypertension (HT), and left ventricular hypertrophy (LVH). The present study assessed in the general population the impact of body weight and visceral obesity on the development of alterations in glucose metabolism and cardiac structure, as well as of elevation in blood pressure. In 1412 subjects randomly selected and representative of the general population of Monza, we assessed twice (in 1990/1991 and 2000/2001) body mass index (BMI); waist circumference; office, home, and 24-hour ambulatory (24-hour) blood pressure, fasting glycemia, and left ventricular mass (echocardiography). New-onset high-risk conditions were DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH. The incidence of new-onset DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH increased progressively from the quintile with the lowest to the quintile with the highest BMI values. Adjusting for confounders, the risk of developing new-onset DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH increased significantly for an increase of 1 kg/m 2 of BMI and 1 cm of waist circumference (respectively, 8.4% [ P <0.01], 9.5% [ P <0.0001], 4.2% [ P <0.0001], 3.9% [ P <0.001], 2.5% [ P <0.05], and 5.1% [ P <0.001] for BMI and 3.2% [ P <0.001], 3.5% [ P <0.0001], 1.8% [ P <0.0001], 1.5% [ P <0.0001], 1.4% [ P <0.001], and 2.6% [ P <0.0001]). These data provide evidence that an increase in BMI and waist circumference is associated with a linearly increased adjusted risk of developing conditions with high cardiovascular risk, such as DM, impaired fasting glucose, in- and out-of-office HT, and LVH.