Comparison of office, home and ambulatory blood pressure measurements in hypertensive and suspected hypertensive SWICOS participants.

PURPOSE: Hypertension should be confirmed with the use of home BP measurement (HBPM) or 24h ambulatory BP measurement (ABPM). The aim of our study was to compare measurements obtained by OBPM, HBPM and ABPM in individuals with elevated OBPM participating in the population-based Swiss Longitudinal Cohort Study (SWICOS). MATERIAL AND METHODS: Participants with OBPM ≥140/90 mmHg assessed their BP using HBPM and ABPM. The cut-off for hypertension was ≥135/85 mmHg for HBPM, ≥130/80 mmHg for ABPM. White-coat hypertension (WCH) was defined as normal HPBM and ABPM in participants not taking antihypertensive drugs. Uncontrolled hypertension was defined as hypertension in HBPM or ABPM despite antihypertensive treatment. RESULTS: Of 72 hypertensive subjects with office BP ≥140/90 mmHg and valid measurements of HBPM and ABPM, 39 were males (aged 62.8 ± 11.8y), 33 were females (aged 57.4 ± 14.2y). Hypertension was confirmed with HBPM and ABPM in 17 participants (24%), with ABPM only in 24 further participants (33%), and with HBPM only in 2 further participants (3%). Participants who had hypertension according to ABPM but not HBPM were younger (59 ± 11 y versus 67 ± 16 y; p < 0.001) and more frequently still working (83% versus 23%; p < 0.001). The prevalence of WCH was 28%. Among the 32 subjects taking antihypertensive drugs, uncontrolled hypertension was found in 49%. CONCLUSION: This population-based study found a high prevalence of WCH and potential uncontrolled hypertension among individuals with elevated OBPM. This study, therefore, supports the ESH recommendations of complementing OBPM by ABPM or HBPM. The use of HBPM instead of ABPM for the confirmation of hypertension in individuals with elevated OBPM might lead to underdiagnosis and uncontrolled hypertension, in particular in the younger working population. In these individuals, this study suggests using ABPM instead of HBPM.

What is already known?Comparing blood pressure measurements in the doctor's office or clinic (OBPM) with out-of-office measurements (either self-measurement at home (HBPM) or ambulatory over 24 hours during both day and night times (ABPM)) improves the accuracy of hypertension diagnosis.Why was the study done?This study was done to provide additional information by comparing HBPM and ABPM in individuals with elevated OPBMs (≥140/≥90mmHg), who participated in the Swiss Longitudinal Cohort Study (SWICOS)What was found?Our study confirmed differences between office and out-of-office measurements. In 60% of the study participants, ABPM or HBPM confirmed the elevated OBPM but only around half of these participants were treated with antihypertensive drugs. A high proportion of the participants (28%) had white coat hypertension.What does this study add?Our study adds to the literature already available on this issue by reporting on data obtained from a cohort of individuals living in a countryside area of Southern Switzerland.This study also showed that HBPM might underestimate BP in the younger working population.How might this impact on clinical practice?The findings of this population-based study support the European Society of Hypertension recommendations for wider use of out-of-office blood pressure measurement for the confirmation of hypertension in individuals with elevated OBPM to avoid underdiagnosis and uncontrolled hypertension.In the young working population, ABPM should be used instead of only HBPM to confirm hypertension.

Two families with hemoglobin Sogn, beta(A11)14 Leu----Arg, in Minnesota and Indiana: hematologic, functional, and biosynthetic features.

Sogn hemoglobinopathy was identified in a young American woman and in a young American man of apparently unrelated families of Norwegian ancestry. Both persons were asymptomatic and without clinical or hematologic manifestations. Hemoglobin Sogn, beta(A11)14 Leu----Arg, is an unstable hemoglobin that may easily be mistaken for hemoglobin S, G, or D by alkaline hemoglobin electrophoresis. These are the first known instances of hemoglobin Sogn outside of Norway. Oxygen affinity is normal. Sogn hemoglobinopathy is an incidental finding that has no adverse implication for the health of heterozygotes.

Accuracy of C-peptide:insulin molar ratio as a measure of hepatic removal of insulin.

We measured transhepatic C-peptide and insulin concentrations in plasma, and hepatic removal of insulin, to examine whether the practice of reporting the C-peptide:insulin molar ratio as a measure of the hepatic removal of insulin is valid. In anesthetized dogs (n = 6), during electromagnetic hepatic blood flow monitoring, endogenous insulin was suppressed with somatostatin, while equimolar proportions of porcine insulin and simian C-peptide (2.4 and 6.0 pmol/kg.min) were infused during two consecutive 45-min periods. Insulin reached steady state within 20 min (t1/2 = 4.5 min); however, C-peptide concentrations continued to rise (t1/2 V 12.5 min). The ratio decreased when the peptide infusion was changed to the higher rate and increased when it was stopped, reflecting the more rapid removal of insulin than of C-peptide. Hepatic removal of insulin remained constant during the two infusion periods (average 60% extraction) and never correlated with the changing molar ratios. Hepatic net flux of insulin correlated with the ratio (P less than 0.05) only while plasma insulin concentrations were rising during constant-rate infusion. We therefore conclude that the molar ratio is not a reliable measure of the hepatic removal of insulin during non-steady states of insulin or C-peptide.

Mechanisms of lidocaine kinetics in the isolated perfused rat liver. I. Effects of continuous infusion.

The mechanisms of time-related reduction in lidocaine clearance were studied using a "one-pass" perfused rat liver system. Lidocaine was infused continuously for a period up to 150 min (concentration ranged from 9.6 to 278 microM). The time required for lidocaine to achieve steady state in the effluent ranged from 20 to 90 min. Analysis of material balance suggested that capacity-limited tissue binding was partially responsible for determining the time to steady state. The characteristic rise of monoethylglycinexylidide to a maximum within 5 min and decline to a stable level during constant lidocaine infusion suggested that the deethylation pathway may be partly deactivated. This observation could be the major determinant for the time-dependent effects of lidocaine elimination. Saturation of metabolism, mainly hydroxylation, and product inhibition by monoethylglycinexylidide did not reduce the extraction of lidocaine significantly. The dose-related reduction in lidocaine elimination is believed to have little contribution to the time effects of lidocaine.

Pharmacokinetic approach to the estimation of hepatic removal of insulin.

We simultaneously measured hepatic insulin removal invasively and estimated hepatic clearance and extraction of insulin pharmacokinetically from cardiac output and peripheral plasma concentrations (relatively) noninvasively. The invasive methods involved continuous electromagnetic measurements of portal venous and hepatic arterial blood flow and simultaneous intermittent sampling of blood from the portal and hepatic veins and femoral artery for assay of insulin concentrations. The noninvasive method assumed that hepatic plasma flow is proportional to cardiac output and that hepatic clearance is a constant fraction of total body clearance of insulin. In anesthetized dogs (n = 6), endogenous insulin was suppressed with somatostatin (800 ng/kg/min) while biosynthetic human insulin (0.25, 0.50, and 1.00 mU/kg/min) was infused to steady state during three consecutive 90-min periods. Insulin concentrations were directly proportional to the infusion rate (p less than 0.01). Hepatic blood flow accounted for 20 +/- 2% of cardiac output. Measured hepatic clearance accounted for 51 +/- 5% of total body clearance of insulin and correlated with the pharmacokinetic estimates (p less than 0.01); the estimates of hepatic clearance ranged from 91 to 114% of the measured values. We conclude that this pharmacokinetic approach, which requires only samples of peripheral blood and estimates of hepatic blood flow, may be used to study the hepatic removal of insulin relatively noninvasively.

Rates of entry of alanine and glycerol and their contribution to glucose synthesis in fasted chickens.

Rates of entry of alanine and glycerol and their contribution to glucose synthesis were studied in 48-h fasted White Leghorn cockerels using primed constant intravenous infusions of L-[U-14C]alanine and [U-14C]glycerol. Entry rates of alanine and glycerol were 112 and 401 mumol/h per kg body weight, respectively. Of the total glucose irreversible loss (entry rate), 1.5 and 6.6% were derived from alanine and glycerol, respectively. The possibilities of the operation of a glyoxylate cycle and omega-oxidation of fatty acids in the fasted chicken are discussed.

Rates of entry and oxidation of D(-)-3-hydroxybutyrate and glucose in fed and fasted chickens.

Rates of entry and oxidation of D(-)-3-hydroxybutyrate (DBHB) and glucose and their contribution to the total metabolic production of CO2 were studied in fed and 48-hr fasted Leghorn roosters using primed constant intravenous infusions of NaH14CO3, D(-)-3-[3-14C]-hydroxybutyrate, and D-[U-14C] glucose. Fasting increased plasma DBHB concentrations sixfold but did not change plasma glucose levels. In both states of nutrition, rates of CO2 production were identical (P greater than .05). Mean fractions of the total CO2 derived from DBHB and glucose in fed and fasted chickens, respectively, were: DBHB, 1.7 and 9.9% (P less than .001); glucose, 29 and 10% (P less than .001). Entry rates of DBHB and glucose in fed chickens were 276 and 5936 mumoles/hr per kg (P less than .001), respectively, and in starved birds were 1703 and 2204 mumoles/hr per kg (P less than .001), respectively. Fasting increased the oxidation rate of DBHB from 124 to 737 mumoles/hr per kg (P less than .001) and decreased the oxidation rate of glucose from 1491 to 525 mumoles/hr per kg (P less than .001). During fasting, glucose homeostasis is maintained in part by concomitant decreases in glucose entry and oxidation rates. The results are discussed with reference to the sparing effect of DBHB on glucose oxidation.

How concentrate feeding affects glucoregulatory hormones in ruminants: implications in bovine ketosis.

Twenty-four feedlot steers and four sheep were fed roughage or grain rations while three other sheep received intraduodenal infusions of amino acids, glucose, volatile fatty acids, and proteins to determine whether the release of plasma glucagon-like immunoreactivity is influenced by dietary factors and the composition of duodenal chyme. Plasma glucagon-like immunoreactivity rose in both cattle and sheep as the proportion of grain in their rations was increased. In response to intraduodenal infusions, only glucose stimulated glucagon-like immunoreactivity release. These experiments demonstrate that plasma glucagon-like immunoreactivity concentrations change in cattle and sheep in response to the amount of grain consumed and that glucagon-like immunoreactivity release is triggered by glucose in intestinal chyme.