Nocturnal dipping is reproducible in the long term

Pregnancy-onset obstructive sleep apnea and ambulatory blood pressure

STUDY OBJECTIVE

Elevated nocturnal blood pressure (BP) increases the risk for hypertensive disorders of pregnancy (HDP). Though obstructive sleep apnea (OSA) increases the risk for HDP, data on OSA, and 24-hour ambulatory blood pressure monitoring (ABPM) in pregnancy are scarce. We aim to examine the BP profile of women with pregnancy-onset OSA.

METHODS

Pregnant women with overweight/obesity and snoring were recruited at <13 weeks gestation and underwent level III home sleep apnea testing and 24-hour ABPM at enrollment and at 31-34 weeks' gestation. Women with OSA at enrollment were excluded. Mean differences in nocturnal BP and 24-hour BP measurements, between women with pregnancy-onset OSA and women without OSA, were computed by multivariable linear regression.

RESULTS

Participants (40/101) had pregnancy-onset OSA (respiratory event index (REI) ≥5 events per hour) in the third trimester. Despite no significant differences in baseline BP, nocturnal systolic and diastolic BP were significantly higher in women with pregnancy-onset OSA compared to women without OSA, after adjusting for multiple covariates (mean difference 5.49 (1.45-9.52) and 3.89 (0.19-7.60), respectively). Differences in systolic BP persisted into the daytime in the OSA group. Lack of nocturnal dipping was highly prevalent in both groups, but the difference was not significant in the adjusted model.

CONCLUSIONS

Pregnancy-onset OSA in the 3rd trimester is associated with elevated nocturnal BP and daytime systolic BP. The lack of nocturnal dipping irrespective of REI cut-off in pregnant women at risk for SDB further demonstrates the limitations of REI in defining pathology in pregnancy.

Blood pressure measurement and nocturnal dipping patterns are heavily affected by body posture through changes in hydrostatic pressure between the arm and the heart

Nocturnal blood pressure (BP) shows the highest predictive power for cardiovascular events. However, there is a poor reproducibility of personalized dipping patterns in single individuals. We hypothesize that changes in body position during sleep cause variations in hydrostatic pressure,leading to incorrect BP values and dipping classifications. 26 subjects aged 18-30 years, as well as 25 participants aged 50 years and older underwent ambulatory BP measurements on the left arm, as well as determination of the hydrostatic pressure difference between the cuff and heart level during BP measurement. We observed that the BP measurement cuff was above the heart level (negative hydrostatic pressure) mostly through the night. Laying on the right side revealed the largest hydrostatic pressure difference and maximum incorrect BP measurement, with a mean of -9.61 mmHg during sleep. Correcting for hydrostatic pressure led to reclassification of nocturnal hypertension in 14 subjects (27.5%). Dipping patterns changed in 19 participants (37.3%). In total, 25 subjects (49.0%) changed either their nocturnal hypertension and/or their dipping classification. Our findings underscore the importance of accounting for hydrostatic pressure in ambulatory BP monitoring. Changes in body posture during sleep provide a plausible reason for the variability seen in nocturnal dipping patterns. Further research should focus on incorporating hydrostatic pressure compensation mechanisms in 24-h BP measurement. Limiting the noticeable effect of hydrostatic pressure differences could greatly improve hypertension diagnosis, classification, and treatment monitoring.

Non-dipping blood pressure pattern is associated with cardiovascular events in a 21-year follow-up study

Non-dipping blood pressure (BP) pattern is a predictor for cardiovascular (CV) events and mortality. We evaluated dipping status change and its association with incidence of non-fatal CV events in middle-aged subjects. The OPERA study was carried out during the years 1991-1993, with a follow-up study 21.7 years later. In this study, we included 452 participants with 24-h ambulatory BP measurements (ABPM) available in both surveys. The study population was divided into four groups according to the dipping pattern change: dipping-dipping (n = 152/33.6%), dipping-non-dipping (n = 198/43.8%), non-dipping-dipping (n = 20/4.4%), and non-dipping-non-dipping (n = 82/18.1%). Sixty-five participants experienced a CV event (14.4%) during the 21.7 (SD 0.8) years of follow-up. The incidence of events was highest (28%) in the non-dipping-non-dipping group, and lowest (6.6%) in the dipping-dipping group (p < 0.001). In Cox regression analyses the covariates were age, sex, total cholesterol, hypertension and use of antihypertensive medication, systolic office BP and ambulatory mean or nighttime systolic BP, as well as the change in the variables during the follow-up period. After adjustments, the association of the non-dipping-non-dipping pattern with CV events compared with the dipping-dipping pattern remained significant (HR 4.01; 95% CI 1.89-8.67, p < 0.001). In summary, non-dipping-non-dipping pattern was associated with non-fatal CV events in the long term, and the effect was independent of the conventional risk factors including office and ambulatory BP levels.

What did we learn from the International Databases on Ambulatory and Home Blood Pressure in Relation to Cardiovascular Outcome?

To assess in individual-person meta-analyses how out-of-office blood pressure (BP) contributes to risk stratification and the management of hypertension, an international consortium set up the International Databases on Ambulatory (IDACO) and Home (IDHOCO) Blood Pressure in Relation to Cardiovascular Outcome. This review summarizes key findings of recent IDACO/IDHOCO articles. Among various BP indexes derived from office and ambulatory BP recordings, the 24-h and nighttime BP level were the best predictors of adverse health outcomes. Second, using the 10-year cardiovascular risk associated with guideline-endorsed office BP thresholds as reference, corresponding thresholds were derived for home and ambulatory BP. Stratified by the underlying cardiovascular risk, the rate of cardiovascular events in white-coat hypertensive patients and matched normotensive controls were not substantially different. The observation that masked hypertension carries a high cardiovascular risk was replicated in Nigerian Blacks, using home BP monitoring. The thresholds for 24-h mean arterial pressure, i.e., the BP component measured by oscillometric devices, delineating normotension, elevated BP and hypertension were <90, 90 to 92 and ≥92 mmHg. At young age, the absolute risk associated with out-of-office BP was low, but the relative risk was high, whereas with advancing age, the relative risk decreased and the absolute risk increased. Using pulse pressure as an exemplary case, the relative risks of death, cardiovascular endpoints and stroke decreased over 3-fold from 55 to 75 years of age, whereas in contrast absolute risk rose 3-fold. In conclusion, IDACO/IDHOCO forcefully support the notion that the pressing need to curb the hypertension pandemic cannot be met without out-of-the-office BP monitoring.

Diagnosis and treatment of arterial hypertension 2021

In the last 4 years, several evidence-based, national, and international guidelines on the management of arterial hypertension have been published, mostly with concordant recommendations, but in some aspects with discordant opinions. This in-depth review takes these guidelines into account but also addresses several new data of interest. Although being somewhat obvious and simple, accurate blood pressure (BP) measurement with validated devices is the cornerstone of the diagnosis of hypertension, but out-of-office BP measurements are of crucial importance as well. Simplified antihypertensive drug treatment such as single-pill combinations enhances the adherence to medication and speeds up the process of getting into the BP target range, a goal not so far adequately respected. Recommended (single-pill) combination therapy includes diuretics as part of the first step of antihypertensive therapy, and updated analysis does not provide evidence to exclude diuretics from this first step because of the recently discussed potential risk of increasing cancer incidence. Target BP goals need to be individualized, according to comorbidities, hypertension-mediated organ damage, coexistence of cardiovascular risk factors (including age), frailty in the elderly, and individual tolerability. There are also concordant recommendations in the guidelines that an office BP between 120 and 140 mm Hg systolic and between 70 and 80 mm Hg diastolic should be achieved. The BP target of Kidney Disease: Improving Global Outcomes for hypertensive patients with chronic kidney disease are not applicable for clinical practice because they heavily rely on 1 study that used a study-specific, nontransferable BP measurement technique and excluded the most common cause of chronic kidney disease, namely, diabetic nephropathy. Actual data even from a prospective trial on chronotherapy have to be disregarded, and antihypertensive medication should not be routinely dosed at bedtime. Rigorously conducted trials justify the revival of renal denervation for treatment of (at least, but not only) uncontrolled and treatment-resistant hypertension.

Short- and Long-Term Reproducibility of Nighttime Blood Pressure Phenotypes and Nocturnal Blood Pressure Reduction

[Figure: see text].

Reproducibility study of nocturnal blood pressure dipping in patients with high cardiovascular risk

It has been shown that in most people there is a physiological reduction in blood pressure during nighttime sleep, it falling by approximately 10% compared to daytime values (dippers). On the other hand, in some people, there is no nighttime reduction (non‐dippers). Various studies have found an association between being a non‐dipper and a higher risk of cardiovascular disease, but few have assessed whether the nocturnal pattern is maintained over time. From the database of the TAHPS study, data were available on 225 patients, each of whom underwent 24‐hour ambulatory blood pressure monitoring (ABPM) on four occasions over a period of 5 months. We studied the reproducibility of the nocturnal BP dipping pattern with mixed linear analysis and also calculated the concordance in the classification of patients as dippers or non‐dippers. The intraclass correlation coefficients between the different ABPM recordings were 0.482 and 0.467 for systolic and diastolic blood pressure, respectively. Two‐thirds (67%) and 70% of the patients classified, respectively, as dippers or non‐dippers based on systolic and diastolic blood pressure readings in the first ABPM recording were found to have the same classification based on the subsequent recordings. We conclude that the reproducibility of nocturnal dipping patterns and concordance of dipper vs non‐dipper status in individual patients is modest and therefore that we should be cautious about recommending treatments or interventions based on these patterns.

Ambulatory Blood Pressure Monitoring to Diagnose and Manage Hypertension

This review portrays how ambulatory blood pressure (BP) monitoring was established and recommended as the method of choice for the assessment of BP and for the rational use of antihypertensive drugs. To establish much-needed diagnostic ambulatory BP thresholds, initial statistical approaches evolved into longitudinal studies of patients and populations, which demonstrated that cardiovascular complications are more closely associated with 24-hour and nighttime BP than with office BP. Studies cross-classifying individuals based on ambulatory and office BP thresholds identified white-coat hypertension, an elevated office BP in the presence of ambulatory normotension as a low-risk condition, whereas its counterpart, masked hypertension, carries a hazard almost as high as ambulatory combined with office hypertension. What clinically matters most is the level of the 24-hour and the nighttime BP, while other BP indexes derived from 24-hour ambulatory BP recordings, on top of the 24-hour and nighttime BP level, add little to risk stratification or hypertension management. Ambulatory BP monitoring is cost-effective. Ambulatory and home BP monitoring are complimentary approaches. Their interchangeability provides great versatility in the clinical implementation of out-of-office BP measurement. We are still waiting for evidence from randomized clinical trials to prove that out-of-office BP monitoring is superior to office BP in adjusting antihypertensive drug treatment and in the prevention of cardiovascular complications. A starting research line, the development of a standardized validation protocol for wearable BP monitoring devices, might facilitate the clinical applicability of ambulatory BP monitoring.

Nocturnal blood pressure measured by home devices: evidence and perspective for clinical application

: Studies using ambulatory blood pressure (BP) monitoring have shown that BP during night-time sleep is a stronger predictor of cardiovascular outcomes than daytime ambulatory or conventional office BP. However, night-time ambulatory BP recordings may interfere with sleep quality because of the device cuff inflation and frequency of measurements. Hence, there is an unmet need for obtaining high quality BP values during sleep. In the last two decades, technological development of home BP devices enabled automated BP measurements during night-time. Preliminary data suggest that nocturnal home BP measurements yield similar BP values and show good agreement in detecting nondippers when compared with ambulatory BP monitoring. Thus, nocturnal home BP measurements might be a reliable and practical alternative to ambulatory BP monitoring to evaluate BP during sleep. As the use of home BP devices is widespread, well accepted by users and has relatively low cost, it may prove to be more feasible and widely available for routine clinical assessment of nocturnal BP. At present, however, data on the prognostic relevance of nocturnal BP measured by home devices, the optimal measurement schedule, and other methodological issues are lacking and await further investigation. This article offers a systematic review of the current evidence on nocturnal home BP, highlights the remaining research questions, and provides preliminary recommendations for application of this novel approach in BP management.

Association of Office and Ambulatory Blood Pressure With Mortality and Cardiovascular Outcomes

Importance

Blood pressure (BP) is a known risk factor for overall mortality and cardiovascular (CV)-specific fatal and nonfatal outcomes. It is uncertain which BP index is most strongly associated with these outcomes.

Objective

To evaluate the association of BP indexes with death and a composite CV event.

Design, Setting, and Participants

Longitudinal population-based cohort study of 11 135 adults from Europe, Asia, and South America with baseline observations collected from May 1988 to May 2010 (last follow-ups, August 2006-October 2016).

Exposures

Blood pressure measured by an observer or an automated office machine; measured for 24 hours, during the day or the night; and the dipping ratio (nighttime divided by daytime readings).

Main Outcomes and Measures

Multivariable-adjusted hazard ratios (HRs) expressed the risk of death or a CV event associated with BP increments of 20/10 mm Hg. Cardiovascular events included CV mortality combined with nonfatal coronary events, heart failure, and stroke. Improvement in model performance was assessed by the change in the area under the curve (AUC).

Results

Among 11 135 participants (median age, 54.7 years, 49.3% women), 2836 participants died (18.5 per 1000 person-years) and 2049 (13.4 per 1000 person-years) experienced a CV event over a median of 13.8 years of follow-up. Both end points were significantly associated with all single systolic BP indexes (P < .001). For nighttime systolic BP level, the HR for total mortality was 1.23 (95% CI, 1.17-1.28) and for CV events, 1.36 (95% CI, 1.30-1.43). For the 24-hour systolic BP level, the HR for total mortality was 1.22 (95% CI, 1.16-1.28) and for CV events, 1.45 (95% CI, 1.37-1.54). With adjustment for any of the other systolic BP indexes, the associations of nighttime and 24-hour systolic BP with the primary outcomes remained statistically significant (HRs ranging from 1.17 [95% CI, 1.10-1.25] to 1.87 [95% CI, 1.62-2.16]). Base models that included single systolic BP indexes yielded an AUC of 0.83 for mortality and 0.84 for the CV outcomes. Adding 24-hour or nighttime systolic BP to base models that included other BP indexes resulted in incremental improvements in the AUC of 0.0013 to 0.0027 for mortality and 0.0031 to 0.0075 for the composite CV outcome. Adding any systolic BP index to models already including nighttime or 24-hour systolic BP did not significantly improve model performance. These findings were consistent for diastolic BP.

Conclusions and Relevance

In this population-based cohort study, higher 24-hour and nighttime blood pressure measurements were significantly associated with greater risks of death and a composite CV outcome, even after adjusting for other office-based or ambulatory blood pressure measurements. Thus, 24-hour and nighttime blood pressure may be considered optimal measurements for estimating CV risk, although statistically, model improvement compared with other blood pressure indexes was small.

Non-dipping blood pressure pattern and new-onset diabetes in a 21-year follow-up

Purpose: Non-dipping blood pressure (BP) pattern has been associated with metabolic changes and cardiovascular events. With regard of diabetes, studies are scarce. Our aim was to investigate if there is an association between changes in dipping patterns and incidence of diabetes. Materials and methods: A 24-h ambulatory BP measurement was recorded in addition to other laboratory measurements, and a questionnaire and physical examination were carried out in the baseline study and after 21-year follow-up among a study population (n = 449) consisting of randomly selected middle-aged Finnish females and males without diabetes. Results: 128 (28.5%) developed diabetes during the follow-up. The incidence of new-onset diabetes was the highest, 41.0%, among those subjects who were non-dippers (their systolic BP declined <10% from daytime to nighttime) in the baseline and also in the follow-up study, while the incidence of diabetes was 19.6% in the dipper - dipper (a nighttime decline of systolic BP 10% or more) group (p = 0.003). The difference remained statistically significant after adjustment with age, sex, body mass index, fasting glucose, triglycerides, and insulin levels, smoking status, 24-h mean systolic BP, high-sensitivity C-reactive protein, estimated glomerular filtration and diuretics use. In logistic regression analysis, the non-dipper - non-dippers were at higher risk of diabetes compared with dipper - dipper group (OR = 2.27, 95% CI: 1.13-4.56, p = 0.022). Conclusions: Our prospective study shows that there is an independent association between non-dipping BP pattern and the incidence of diabetes in a 21-year follow-up.

Prospective analysis of the association of ambulatory blood pressure characteristics with incident chronic kidney disease

OBJECTIVE

Ambulatory blood pressure measurement allows quantification of diurnal changes in blood pressure. While decreased nocturnal blood pressure dipping and elevated morning blood pressure surge are associated with an increased risk of cardiovascular events, the utility of ambulatory blood pressure measurements to predict renal events is unclear. African Americans, in addition to having an increased risk of chronic kidney disease (CKD), also have an increased prevalence of hypertension. Thus, we selected an African American population to study the association of ambulatory blood pressure parameters with incidence of CKD.

METHODS

Prospective cohort study of 603 participants with normal renal function enrolled in the Jackson Heart Study who underwent baseline 24-h ambulatory blood pressure monitoring between 2000 and 2004, with median follow-up of 8.1 years. We analyzed the association of nocturnal dipping and morning surge with both incident CKD [estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m] and annual rate of eGFR decline. In additional analyses, we examined the relation of nocturnal, daytime, white-coat, and masked hypertension with CKD incidence.

RESULTS

We found that 10% higher nocturnal dipping was significantly associated with a decreased risk of incident CKD [odds ratio (OR) 0.55, 95% confidence interval (CI) 0.32-0.96] and a 0.4 ml/min per 1.73 m slower annual decline in eGFR. Morning surge was not associated with the incidence of CKD. Additional analyses revealed that isolated nocturnal hypertension and mean asleep SBP were associated with a nonsignificantly higher risk of CKD (OR 2.34, 95% CI 0.90-6.08) and (OR 1.31, 95% CI 0.99-1.72), respectively, in fully adjusted models.

CONCLUSIONS

Loss of nocturnal blood pressure dipping, but not morning blood pressure surge, may promote the decline in GFR and increase the risk for development of CKD in high-risk individuals.

Reproducibility of blood pressure dipping: relation to day-to-day variability in sleep quality

Previous studies of the reproducibility of blood pressure (BP) dipping have yielded inconsistent results. Few have examined factors that may influence day-to-day differences in dipping. Ambulatory BP monitoring was performed on three occasions, approximately 1 week apart, in 115 untreated adult subjects with elevated clinic BPs. The mean ± standard deviation BP dip was 18 ± 7/15 ± 5 mm Hg (sleep/awake BP ratio = 0.87 ± 0.05/0.82 ± 0.06), with a median (interquartile range) day-to-day variation of 5.2 (3.1-8.1)/4.3 (2.8-5.6) mm Hg. There was no decrease in variability with successive measurements. The reproducibility coefficient (5.6 [95% confidence interval, 5.1-6.1] mm Hg) was greater and the intraclass correlation coefficient (0.53 [95% confidence interval, 0.42-0.63]) was smaller for the systolic dip than for 24-hour or awake systolic BPs, suggesting greater day-to-day variability in dipping. Variability in systolic dipping was greater in subjects with higher awake BP, but was not related to age, gender, race, or body mass index. Within individuals, day-to-day variations in dipping were related to variations in the fragmentation index (P < .001), a measure of sleep quality. Although mean 24-hour and awake BPs were relatively stable over repeated monitoring days, our study confirms substantial variability in BP dipping. Day-to-day differences in dipping are related to sleep quality.

Nocturnal medications dosing: does it really make a difference in blood pressure control among patients with chronic kidney disease?

Ambulatory blood pressure (BP) monitoring is superior to clinic BP monitoring in predicting long-term consequences of hypertension. This has raised interest in diurnal variation in BP and elevation in nighttime BP as a prognostic and therapeutic target. Several studies have identified prevalence of nocturnal hypertension in patients with accelerated progression of chronic kidney disease and target organ damage. Some studies suggest that nocturnal BP can be lowered by changing administration of antihypertensive medication to bed time; whether that results in retarding kidney disease progression is not very clear. Further research is needed to determine if certain classes of medications or interventions are superior in controlling nocturnal hypertension, and protocols need to be developed to screen patients for monitoring nocturnal BP. Further studies are needed to evaluate long-term renal outcomes of evening dosing in patients with nocturnal hypertension and chronic kidney disease.

Assessment of the diurnal blood pressure profile and detection of non-dippers based on home or ambulatory monitoring

BACKGROUND

A unique advantage of ambulatory blood pressure (ABP) monitoring is the assessment of nocturnal blood pressure (BP) and the detection of non-dippers. This study assessed nocturnal BP and non-dippers using a novel home BP (HBP) monitor.

METHODS

Eighty-one hypertensives performed within 2 weeks ABP (24-h, Microlife WatchBP O3) and HBP monitoring (Microlife WatchBPN) during daytime (6 days, duplicate morning and evening measurements) and nighttime (automated asleep measurements, 3 nights, 3 readings/night). Patients' preference in using ABP or HBP was assessed by a questionnaire.

RESULTS

Strong associations were found between ABP and HBP (intraclass correlation coefficients for awake systolic/diastolic 0.75/0.81; asleep 0.87/0.85). No statistically significant difference was found between HBP and ABP (mean difference ± SD awake systolic/diastolic 1.5 ± 10.1/-1.1 ± 6.0 mm Hg, P = 0.20/0.09; asleep -0.4 ± 7.8/-1.0 ± 5.3, P = 0.63/0.09). There was substantial agreement (74%, kappa 0.2) between ABP and HBP in the detection of non-dippers, which was similar to the previously reported test-retest reproducibility of repeated ABP monitoring in the diagnosis of non-dippers. Moderate to severe disturbance from ABP monitoring was reported by 18% of the participants and severe restriction of their daily activities by 9, vs. 3 and 1.5%, respectively for HBP (P < 0.001/ <0.01, for comparisons respectively). Nighttime BP monitoring and cuff discomfort were the main complaints for ABP (46 and 32%, respectively) and HBP (34 and 28%), whereas 89% reported more nighttime sleep disturbance by ABP than HBP (P < 0.001).

CONCLUSIONS

HBP monitoring appears to be a reliable and well accepted by users alternative to ABP for the assessment of nocturnal BP and the detection of non-dippers.

Orthostatic hypotension is associated with nocturnal change in systolic blood pressure

BACKGROUND

The circadian pattern of blood pressure (BP) has yet to be defined among individuals with orthostatic hypotension (OH). The objective of this study was to evaluate whether OH is associated with nocturnal change in systolic BP.

METHODS

In a prospective study, we evaluated patients who were referred for 24-h ambulatory blood pressure monitoring (ABPM). All subjects underwent orthostatic BP testing before recording their respective 24-h ABPM.

RESULTS

The study includes 185 subjects, 114 males, mean age 58 ± 18 years (range 19-89). Participants were classified, based on pattern of systolic BP changes at night, as dippers (greater than 10% decrease; n = 74), nondippers (0-10% decrease; n = 77), and reverse-dippers (increase; n = 34). Nineteen patients (10.3%) had OH. Almost all participants with OH (95%) had an abnormal diurnal BP pattern, and most of them (58%) were reverse-dippers, whereas only 56% of the participants without OH had an abnormal diurnal BP variation, and only 14% were reverse-dippers (P < 0.001). Systolic BP decreased with upright posture by 12 and 2 mm Hg in the reverse-dippers and the nondippers, respectively, and increased by 2 mm Hg in the dippers (P < 0.001). Postural changes in systolic BP were inversely related to the changes between day and night BP readings(r = -0.43; P < 0.01). In a multivariate linear regression analysis, orthostatic BP change, use of ≥2 antihypertensive drugs and female sex were related to nocturnal BP changes.

CONCLUSIONS

The decrease in BP during upright posture may be a marker of nondipping or reverse-dipping pattern of diurnal BP.

The associations between G972R polymorphism of the IRS-1 gene, insulin resistance, salt sensitivity and non-dipper hypertension

The aim of this study was to assess the association between G972R polymorphism of the insulin receptor substrate-1 (IRS-1) gene and the circadian variation in blood pressure, insulin sensitivity and salt sensitivity in subjects with uncomplicated, never-treated essential hypertension receiving low-, normal- and high-salt diets. The study was performed on 115 subjects aged 27.48±5.1 years with never-treated, uncomplicated hypertension. In the 7-day consecutive period of time, subjects received a normal-, low- and high-salt diet. At the end of each dietary regimen, the following parameters were recorded: 24-h blood pressure monitoring, lipid profile, insulin level, glucose level, aldosterone level and plasma renin activity. Insulin resistance was evaluated by the homeostasis model assessment (HOMA). In comparison with Gly/Gly carriers, subjects with the G972R polymorphism had higher concentrations of total and LDL cholesterol and triglycerides and HOMA but lower HDL cholesterol. On a high-salt diet, patients with the G972R polymorphism had an increased risk for insulin resistance (odds ratio (OR)=11.42, 95% confidence interval (CI) 7.68-28.44), salt sensitivity (OR=5.38, 95% CI 1.14-25.34) and non-dipper hypertension (OR=3.6, 95% CI 1.07-12.09). Regardless of the dietary salt intake, blood pressure values were similar between G972R and Gly/Gly carriers. In conclusion, the results of our study suggest that the G972R polymorphism of the IRS-1 gene is associated with insulin resistance, salt sensitivity and non-dipper hypertension.