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1.
A large proportion, from 30% to 50%, of diabetic patients frequently manifests loss of the normal diurnal variation of blood pressure, i.e. their blood pressure does not show at least 10% fall at night (non-dippers). It has been demonstrated that non-dippers are at increased risk of end-organ damage, in particular, renal and cardiovascular complications. As no reliable means of reversing impaired blood pressure variation has been established so far, we aimed at assessing the effect of a long-acting angiotensin-converting enzyme (ACE) inhibitor trandolapril on the disturbed circadian blood pressure rhythm in diabetics without hypertension or nephropathy. A total of 18 type 1 diabetes patients (8 male, 10 female), aged 33.5+/-4.8, with duration of diabetes 5.8+/-2.8 years and HbA(1c) 6.6+/-0.4% (range 5.8--7.1%) were enrolled into the study. Ten well-matched type 1 diabetes patients served as an untreated control group. Twenty-four-hour ambulatory blood pressure measurements (ABPM) were performed thrice in each subject: before trandolapril, 2 mg once daily in the morning, was started; after the first dose of the drug; and after 2 weeks of the treatment. Mean (+/-S.D.) values of systolic, diastolic blood pressure, night fall in systolic, and diastolic blood pressure in the treatment group were (1) at baseline: 124.0+/-5.8 mm Hg, 89.3+/-4.2 mm Hg, 3.0+/-2.2%, 5.1+/-3.8%; (2) after the first dose: 116.1+/-7.6 mm Hg (P<.01 vs. baseline), 82.6+/-6.7 mm Hg (P<.01 vs. baseline), 4.2+/-2.6%, 4.7+/-2.5%; and (3) after 14-day treatment: 116.6+/-8.1 mm Hg (P<.01 vs. baseline), 76.9+/-9.6 mm Hg (P<.01 vs. baseline), 17.6+/-6.9% (P<.01 vs. baseline and after 24-h values), 19.4+/-8.0% (P<.01 vs. baseline and after 24-h values), respectively. ABPM results for the untreated controls were similar in all three measurements. In conclusion, within 14 days of trandolapril treatment, circadian blood pressure variation was successfully restored in normoalbuminuric normotensive insulin-dependent diabetic patients.  相似文献   

2.
Abstract. Objective. To test the hypothesis that normoal-buminuric type 1 diabetic patients segregate into groups with normal and elevated ambulatory blood pressure. To evaluate diurnal variation of blood pressure assessed by individual or fixed night-time periods. Design. Cross-sectional study. Setting. Tertiary referral centre. Subjects. Inclusion criteria for type 1 diabetic patients (n = 33): normal urinary albumin excretion (UAE age < 45 < 20 μg min?1), diabetes duration ≤ 20 years, age 45 years. Healthy controls (n = 33) were matched for sex and age. Main outcome measure. Twenty-four hour, day-time, night-time and night/day ratio of ambulatory blood pressure. Results. Twenty-four-hour blood pressure in diabetic patients did not differ significantly from a normal distribution. The 24-h systolic blood pressure was higher in diabetic patients than in healthy controls (difference: 6 mmHg, 95% confidence interval (CI) from 1 to 10 mmHg, P < 0.05), while no significant differences were found for diastolic values. The 24-h systolic blood pressure in diabetic patients with UAE above the median value (5.8 μg min?1) was higher than for those with lower UAE (difference: 7 mmHg, 95% CI from 0.5 to 13 mmHg, P < 0.05). The night/day ratio of diastolic blood pressure based on individual informations of the night period was (mean ± SD) 80 ± 6% in diabetic patients and 78 ± 8% in controls (difference: 2%, 95% CI from ?1 to 5%, not significant [NS]). This ratio increase significantly (P < 0.00001) to 90 ± 5% in diabetes and to 84 ± 7% in controls if a fixed night period from 22.30 hours to 06.30 hours was assumed. Conclusions. It was not possible to identify a well-separated group of normoalbuminuric type 1 diabetic patients with elevated ambulatory blood pressure. Values of UAE above the median in diabetic patients are associated with higher ambulatory blood pressure. Assessment of the night/day variation from fixed time-points should be abandoned because this leads to a serious underestimation of the nocturnal reduction in blood pressure.  相似文献   

3.
With the objective to examine patterns of blood pressure (BP) in normotensive and normoalbuminuric Type 1 diabetic patients during 24 h ambulatory blood pressure monitoring (ABPM) we studied 28 Type 1 diabetic patients aged 27+/-7.1 years with a disease duration of 9+/-6.6 years, and 28 non-diabetic normotensive subjects aged 25+/-6.5 years matched to the diabetic group for age, gender, skin color, weight, height, body mass index, clinic BP and absence of microalbuminuria. Systolic BP (sBP) and diastolic BP (dBP) were recorded for 24 h, daytime and nighttime. SBP and dBP burden, night/day BP ratios and percent nighttime BP fall were determined. Subjects with a nocturnal fall in either sBP or dBP of less than 10% of daytime values were classified as non-dippers. Both sBP (111+/-7.1 vs. 104+/-9 mmHg; P=0.003) and dBP nighttime (66+/-6.1 vs. 61+/-5.3 mmHg; P=0.001) were higher in diabetic patients than non-diabetic subjects. Night/day ratios for sBP (0.93+/-0.04 vs. 0.89+/-0.05; P=0.006) and dBP (0.86+/-0.06 vs. 0.82+/-0.06; P=0.007) were higher in diabetics. The loss of a fall in sBP was more prevalent in diabetic subjects (78 vs. 39%; P=0.007). Non-dippers for sBP and dBP in the diabetic group had higher BP burden during the nighttime (21.4+/-16.6 vs. 3.2+/-3.9%; P=0.01 and 21.9+/-10 vs. 3.7+/-5.5%; P<0.001, respectively). Our data demonstrate higher sBP and dBP during the nighttime and loss of the nocturnal fall in BP in Type 1 diabetic patients. Further prospective studies are needed to define if high BP burden in diabetic non-dippers during the night could represent a risk for nephropathy and cardiovascular disease.  相似文献   

4.
To investigate the relationship between diabetic retinopathy (DR) and 24-h ambulatory blood pressure (ABP) in a cohort of normotensive, normoalbuminuric type 1 diabetic patients. This is a 6.1+/-3.3 year prospective study of 44 normotensive, normoalbuminuric type 1 diabetic patients. ABP was measured at the beginning and at the end of the study. Measurements of urinary albumin excretion rate (UAER) and direct and indirect ophthalmoscopy after mydriasis were performed at the start and end of the study and at least once a year. DR was observed in 12 patients at baseline. At the end of the study, eight of these patients had progressed to more advanced stages of retinopathy. Four patients developed retinopathy after the study began. These patients were grouped and classified as progressors. At baseline, progressors were older, had longer duration of diabetes, higher levels of UAER, and higher 24-h diastolic (P=0.03) and diurnal diastolic blood pressure (P=0.03). UAER and diastolic blood pressure (24h or day) remained significantly associated with development and progression of DR after multivariate analysis. High normal ABP was associated with the development or progression of DR in this cohort of normotensive, normoalbuminuric type 1 diabetic patients. Abnormalities in blood pressure homeostasis could indicate higher susceptibility to DR.  相似文献   

5.
BACKGROUND: To address whether type 1 diabetic patients with type 2 diabetic first degree relatives are different from others in terms of cardiovascular risk factors, insulin resistance and daily insulin dosage. METHODS: We studied 18 type 1 diabetic patients with type 2 diabetic first degree relatives and 36 type 1 diabetic patients without such relatives. Patients with diabetic complications (including microalbuminuria) were excluded. The groups were similar in terms of baseline characteristics. We measured systolic and diastolic blood pressures, body mass index, waist circumference, total cholesterol, triglycerides, LDL, VLDL, HDL, daily insulin dosage and insulin sensitivity. Insulin sensitivity was tested using insulin tolerance test. RESULTS: Type 1 diabetic patients having first degree relatives with type 2 diabetes had significantly higher systolic and diastolic blood pressures (although within the normal range) than others (p < 0.001). They were more insulin resistant according to insulin tolerance test and were using higher daily insulin dosages. In this group, waist circumference, triglyceride and VLDL levels also tended to be higher, but differences were not significant statistically. Total cholesterol, LDL and HDL levels were similar in both groups. CONCLUSION: Family history of type 2 diabetes increases blood pressure and decreases insulin sensitivity in type 1 diabetic patients. Thus such patients should be treated more aggressively in terms of both cardiovascular risk factors and glucose control.  相似文献   

6.
Progression of diabetic retinopathy (DR) occurs at least temporarily during pregnancy and postpartum. The pathogenetic mechanisms of DR progression during pregnancy are not fully understood. Several factors related to metabolic changes (hyperglycaemia), diabetes itself (duration of diabetes before conception, baseline status of DR), pregnancy physiology (hypervolaemia and hypercoagulation, impaired retinal autoregulation) and pregnancy complications (pre-eclampsia) seem to play important roles in the progression of DR during pregnancy. On the other hand, systemic angiopoietic and vasoactive factors seem to have minor role in the deterioration of DR during that time period. Good glycaemic control, normotension, lack of nephropathy as well as lack of pre-proliferative/proliferative changes of DR are good prognostic factors as regards the progression of DR during pregnancy. However, pregnancy seems to have no long-term detrimental effects as regards the progression of DR unless it has proceeded to pre-proliferative and proliferative phases.  相似文献   

7.
BACKGROUND: Due to large beat-to-beat blood pressure variation the use of 24-h ambulatory blood pressure monitoring in patients with atrial fibrillation has been questioned. METHODS: Repeatability and variability of 24-h ambulatory blood pressure (Accutraccer II or Diasys Integra), and daily blood pressure variation was examined in 42 patients aged 51-81 (median 73.5) years admitted for elective electrocardioversion of atrial fibrillation. RESULTS: Before cardioversion 24-h ambulatory systolic blood pressure was slightly lower and nocturnal blood pressure reduction was larger in the group of patients who achieved sinus rhythm than in the group who maintained atrial fibrillation (11.5/10.5 versus 4.1/4.7 mmHg; P < 0.05). No statistically significant change was observed in ambulatory blood pressure after cardioversion in any of the two groups. Blood pressure variability (SD/mean) was 10-14% both in patients with and without conversion to sinus rhythm. Coefficient of repeatability (2 SD of difference) was 13.6 mmHg (16.6%) for diastolic blood pressure and 30.2 mmHg (24.7%) for systolic blood pressure in patients with normalized heart rhythm and 17.0 and 29.0 mmHg (21.5 and 22.4%) in patients with maintained atrial fibrillation, respectively. CONCLUSION: Ambulatory blood pressure monitoring provides data with similar variability and repeatability in patients with atrial fibrillation as in subjects with normal cardiac rhythm. Twenty-four-hour ambulatory blood pressure measurement is applicable in atrial fibrillation in the same way as during sinus rhythm.  相似文献   

8.
We investigated whether blood pressures are higher in normotensive offspring of hypertensive parents than in normotensive offspring of normotensive parents outside the physician's office and, if so, whether these higher blood pressures are dependent on the level of dietary sodium intake. We compared 24-hour ambulatory blood pressure profiles between 11 normotensive sons of two hypertensive parents and 11 normotensive sons of two normotensive parents; profiles were recorded after 1 week of a low sodium diet (10 meq/day) and after 1 week of a high sodium diet (200 meq/day). The sons of hypertensive parents were on average 6 years older than the sons of normotensive parents (47 +/- 5 [SD] versus 41 +/- 4 years, p < 0.05). The shift from low to high sodium diet did not significantly change the magnitude of differences in office or ambulatory blood pressures between the groups (i.e., no group-by-diet interaction); thus, we assessed group effects by contrasting blood pressure means for each group pooled across diets. Age-adjusted office blood pressure was higher in sons of hypertensive parents than in sons of normotensive parents (116 +/- 7/80 +/- 6 versus 111 +/- 7/75 +/- 6 mm Hg; p = 0.020 for systolic and p = 0.003 for diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
To characterise the relationship between diurnal blood pressure and the subsequent increase of urinary albumin excretion (UAE) in normotensive normoalbuminuric type 1 diabetic patients, ambulatory blood pressure monitoring (ABPM) was performed in 53 patients, who were then followed for 5 years. Albumin excretion rate changed from 12.4 (8.9-17.2) to 29.3 (15.2-47.0) mg/day. Macroalbuminuria developed in 2 (3.8%), microalbuminuria in 22 (41.5%) patients, 29 (54.7%) remained normoalbuminuric. Night-time diastolic blood pressure was significantly higher (64.3+/-6.5 vs. 60.9+/-5.5 mmHg, P<0.05), diastolic diurnal index significantly lower (15.5+/-9.7 vs. 22.3+/-6.2%, P<0.01) in patients who later progressed to micro- or macroalbuminuria. Diastolic diurnal index (r=-0.40; P<0.01) and nocturnal diastolic pressure (r=0.35; P<0.01) were correlated to the change in albumin excretion. In a multivariate analysis model with the change of albumin excretion as dependent, and means and diurnal indices of systolic and diastolic blood pressure, baseline UAE, cholesterol, triglycerides, HbA1c and retinopathy as independent parameters (r=0.68; P=0.001), diurnal index for diastolic blood pressure (beta=-0.30; r=0.013), baseline HbA1c (beta=0.32; P=0.010) and retinopathy (beta=0.44; P=0.001) were significant independent correlates. We conclude that the relative increase of nocturnal blood pressure is associated with the subsequent increase of albuminuria, which in turn is predictive of overt diabetic nephropathy.  相似文献   

10.
Twenty-four-hour blood pressure monitoring and effects of indapamide   总被引:1,自引:0,他引:1  
Twenty-four-hour blood pressure (BP) monitoring with a noninvasive device (Kontron) has been used to assess the effect of a single dose of indapamide in a group of patients with essential hypertension. Originally 23 patients were selected. Three patients withdrew from the study because of refusal to go through the second 24-hour recording. Eight of the remaining patients had to be excluded for technical reasons, which left 12 patients available for analysis. All patients received a single dose of indapamide, 2.5 mg/day. Before treatment began, a 24-hour BP control was performed, and a second one a month later (37 +/- 8 days). The age of the patients was 46 +/- 10 years. Diurnal BP (8 am to 10 pm) and heart rate were, respectively, 148 +/- 15/101 +/- 6 mmHg and 79 +/- 9 beats/min; night BP (10 pm to 8 am) was 131 +/- 15/88 +/- 7 mmHg and heart rate 71 +/- 10 beats/min. After therapy, diurnal BP was 131 +/- 15/92 +/- 7 mmHg (-15 +/- 7/-8 +/- 4: p less than 0.0001/p less than 0.0001); heart rate 82 +/- 8 beats/min (difference not significant); night BP was 115 +/- 13/80 +/- 8 mmHg (-16 +/- 11/-8 +/- 7: p less than 0.0001/p less than 0.0001) and heart rate 70 +/- 9 beats/min (difference not significant). Twenty-four-hour systolic work values were 106 +/- 15 at the beginning of the trial and 96 +/- 14 (-9.7 +/- 14; p less than 0.05) after 1 month of indapamide treatment. Variability did not change with treatment.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
A number of studies have shown changes and even an inversion of the diurnal cycle in certain affections: Cushing's syndrome, pheochromocytoma, severe renal failure, autonomous nervous system disorders, pre eclampsia etc.... The authors studied diurnal and nocturnal variations of blood pressure in type I diabetics. Twenty-nine normotensive (WHO criteria) type I diabetics (NTD) average age 34.9 +/- 11 years, with diabetes of 13.6 +/- 8 years standing, and 118 normotensive non-diabetics (NT) aged 20 to 60 years (distributed by decennies according to age and sex) were studied. The systolic (SBP) and diastolic blood pressures (DBP) were recorded at rest in the decubitus position by the phase V indirect auscultatory method and during ambulatory monitoring (automatic Spacelabs no. degrees 90207 device) every 15 minutes during the daytime and 20 minutes during the night. The mean values were studied; the values of the heart rates were identical in the NTD and NT populations. Significant difference in SBP between the Nt and NTD were recorded: during daytime there was no difference either in SBP or DPB; during the night, there was a significant difference in SBP. A study of the day-night differences both in absolute and in relative values (day-night difference with respect to daytime values as a percentage) did not show any statistically significant differences between the two populations. Abnormalities of the 24 hour profile, defined as absence of a 5 mmHg fall in nocturnal BP values, were looked for but there were no differences between the NT and NTD subjects.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
13.
Eight male normoproteinuric Type I (insulin dependent) diabetic patients and eight age- and sex-matched non-diabetic control subjects were studied for their response to exercise. Systolic blood pressure showed an exaggerated response to exercise in the diabetic group (median 123, range 98-151 mmHg, pre-exercise vs. 187, 163-217 mmHg, immediately post exercise P less than 0.01) compared to the control group (median 112 (100-145) pre-exercise, 153 (138-178) post exercise). Resting noradrenaline levels were lower in the diabetic (D) compared with the control (C) group (D: 1.66, 0.55-3.92 nmol/l vs. C: 2.96, 2.04-4.49 nmol/l, P less than 0.02). Levels rose during exercise by 79% (25-307%) and 43% (4-90%) respectively (NS). Resting urinary sodium was raised in the diabetic group and fell during exercise (P less than 0.05) (D: 146, 74-244 mumol/min, C: 108.5 (83.4-151.0) pre-exercise vs. D: 73, 48-264 mumol/min, C: 81.7 (23.0-92.0) post exercise). Resting atrial natriuretic peptide levels were lower in the diabetic group (D: 10.1, 4.3-16.9 pmol/l vs. C: 16.0, 9.5-22.9 pmol/l, P less than 0.02) and levels rose significantly in both groups during exercise (D: 25.9, 5.2-38.9 pmol/l vs. C: 28.6, 17.3-47.2 pmol/l, P less than 0.05). We conclude that exercise provokes an exaggerated rise in systolic blood pressure and decrease in urinary sodium excretion in normoalbuminuric diabetic patients. These findings may reflect increased sensitivity to the renin-angiotensin-aldosterone system. Reduced atrial natriuretic peptide levels may stimulate sodium retention and increased blood pressure in early diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
Summary The antihypertensive effect of a single dose of 240 mg sustained-release (S-R) verapamil was investigated by ambulatory blood pressure (BP) monitoring in 13 patients with mild to moderate essential hypertension. Following a 2-week washout period, 24-hour BP monitoring was carried out with a Spacelabs ICR 5300 device following random administration of a tablet of S-R verapamil or placebo; BP recording was repeated after crossover 3 to 7 days later. Average whole-day systolic and diastolic BPs were significantly lower after verapamil (130.1±2.6/87.1±1.2 mmHg) than after placebo (142.1±3.3/95.8±2.1 mmHg) (p<0.01). Mean waking BP was 146.4±3.6/99.1±2.2 mmHg after placebo and 135.2±3.3/90.5±1.7 mmHg after verapamil (p<0.01); during sleeping hours BP was 133.8±3.1/88.7±2.6 mmHg following placebo and 122.2±2.3/80.9±1.8 mmHg following verapamil (p<0.01). Blood pressure profile was significantly reduced by verapamil up to 20 hours after tablet administration, while from 21 to 24 hours after drug intake BP values were similar to placebo. Response to verapamil was not correlated to the pretreatment BP values and to the patient's age. In summary, this study suggests that acute administration of 240 mg S-R verapamil in hypertensive patients produces a BP reduction during 24-hour, daytime, and nighttime periods. The hypotensive efficacy is preserved for many hours after tablet intake and seems to be due to individual variation in cardiovascular reactivity to the drug.  相似文献   

15.
OBJECTIVES: To elucidate the prevalence of nondipping in 24 h blood pressure monitoring (BPM) during hospital care with respect to antihypertensive drug therapy, diabetes, renal artery stenosis, and inverse diurnal blood pressure profiles. METHODS: Prospective, consecutive categorization of routine 24 h BPM was performed according to nondipping, drug therapy, normotension, severity of hypertension, diabetes, and inverse diurnal profile for 2 years. Retrospective analysis of patients examined by intraarterial renal artery angiography were performed. Nondipping was defined as a drop in night-time blood pressure (2200-0600 h) by less than 10% of the daytime values. Normotension was considered a daytime 24 h BPM value below 135/85 mmHg without antihypertensive therapy. RESULTS: We categorized 2105 24 h BPM protocols for patients of mean age 59 years. Nondipping was found for 26% of the normotensives, 38% of hypertensive patients not being administered medication, and 48% of drug-treated hypertensives. The significant increase in nondipping among patients under drug therapy applied for patients with daytime blood pressures below and above 135/85 mmHg and was thus independent of the severity of hypertension. Among the subgroup of 561 predominantly type 2 diabetic patients the prevalence of nondipping was increased significantly only for those patients who were hypertensive and being administered antihypertensive drugs. Subgroup analysis of patients using intraarterial angiography did not find different prevalences of nondipping for patients with and without renal artery stenosis. Patients with an inverse diurnal blood pressure profile and an increase in night-time blood pressure by more than 5% of the daytime values presented as a high-risk group because of morbidity associated with renal, cardiac, and cerebral disease. CONCLUSION: Nondipping is a common phenomenon among hospital patients. Drug therapy of hypertension should be directed not only towards the daytime blood pressure, but also toward alleviation of night-time hypertension.  相似文献   

16.
We performed a battery of cardiovascular reflex tests, 24-h ambulatory blood pressure (AMBP) and 24-h urinary albumin excretion (UAE) in 116 normoalbuminuric and normotensive patients with Type 1 diabetes. Tests of heart rate variation (HRV) included the coefficient of variation (CV) and the low-frequency (LF), mid-frequency (MF), and high-frequency (HF) bands of spectral analysis at rest, HRV during deep breathing (CV, mean circular resultant — MCR), Valsalva ratio, and maximum/minimum 30:15 ratio. Autonomic neuropathy, characterized as an abnormality of more than two tests, was found in 33 patients. Patients with neuropathy compared to those without neuropathy showed significantly higher mean day and night diastolic blood pressure (dBP), mean systolic night blood pressure (sBP), and mean day and night heart rate (HR). Mean night dBP was inversely related to MF, HF, and HRV during deep breathing; mean day dBP and mean night sBP to HF; mean night HR to CV at rest, MF, HF, HRV during deep breathing, 30:15 ratio; mean day HR to HF, HRV during deep breathing, Valsalva, and 30:15 ratio. Mean 24-h UAE was not significantly different in neuropathic than in nonneuropathic patients. UAE was inversely related to CV at rest and HF. In the stepwise multiple regression analysis, reduced MF, HF, HRV during deep breathing, and high levels of UAE and HbA1c were associated with high night dBP. Autonomic neuropathy is already present in normotensive Type 1 diabetic patients at the normoalbuminuric stage and related to BP and albuminuria.  相似文献   

17.
Forty-four normotensive females, who were selected on the basis of lower prevailing potassium intake, participated in a two-period crossover study to assess the effects of potassium supplementation on blood pressure. They were randomly allocated to one of two groups who took either 80 mmol/day of KCl (Slow-K, Ciba Geigy), or matching placebo, for the first of two 4-week treatment periods. The treatments were reversed during the second 4-week period. Despite significant increases in both urinary and plasma potassium no consistent fall in blood pressure was seen during 80 mmol/day potassium intake.  相似文献   

18.
Hypertensive disease in pregnancy represents a significant health problem in the world, and ranks second only to thromboembolism as a cause of maternal mortality in the USA. In addition, hypertension is associated with both perinatal morbidity and mortality secondary to direct effects on the fetus as well as the iatrogenic preterm deliveries performed for maternal indications. Conventional (office, mercury column or aneroid manometry) blood pressure measurement is the most common screening test performed during prenatal visits. During the past several years, investigators have focused on the use of 24-h ambulatory and automated self (or home) blood pressure monitoring during pregnancy. This review article summarizes the current literature on both ambulatory and home blood pressure monitoring in pregnancy and how they relate to various clinical aspects of hypertension in pregnancy.  相似文献   

19.

Aims/hypothesis  

We studied the progression of diabetic retinopathy during pregnancy in women with type 2 diabetes.  相似文献   

20.
Twenty-four-hour ambulatory blood pressure in shift workers   总被引:4,自引:0,他引:4  
Blood pressure and heart rate of 15 male shift workers were measured every 15 minutes for 24 hours during three work shifts: morning, 4:00 AM to noon; afternoon, noon to 8:00 PM; and night, 8:00 PM to 4:00 AM. For each shift, 24-hour systolic and diastolic blood pressure showed a large "trough" (the low pressure span) and a continuous range of elevated pressure (the high pressure span). Fourier series were used to model the 24-hour blood pressure profiles. A careful examination of the residuals (measured minus predicted pressures) showed that four harmonics were necessary to describe the data accurately. The model enabled localization in each blood pressure profile of the high and low pressure spans that did not coincide with the subject's work and rest periods. The time and slope of blood pressure entering and leaving these spans could also be individually determined. Mean blood pressure during the high pressure span was the same for the three shifts, but mean blood pressure during the low pressure span was lower when the subject worked in the afternoon. During that shift, the systolic blood pressure slopes entering and leaving the low pressure span were steeper than during the two other shifts. The high pressure span was longest during the night shift and shortest during the afternoon shift. Therefore, a change in the working time profoundly perturbed the 24-hour blood pressure profile.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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