Elevated sodium-lithium countertransport activity in erythrocytes is predictive of the development of microalbuminuria in IDDM

Summary Pathogenetic mechanisms other than the quality of metabolic control may play a role in the development of diabetic nephropathy. Some cross-sectional studies have shown that elevated erythrocyte sodium-lithium countertransport (Na ⁺ /Li ⁺ CT) activity may be linked to incipient or overt nephropathy in insulin-dependent diabetic (IDDM) patients. The aim of the present work was to ascertain if high erythrocyte Na ⁺ /Li ⁺ CT activity anticipates the development of microalbuminuria in IDDM patients. Evaluation of this cation transport system was carried out in 159 normotensive, normoalbuminuric IDDM patients, who were divided into two groups: those with values above (Group A) and those with values below (Group B) the median level in the overall population (300 μmol/erythrocytes × h). A total of 79 patients in Group A and 80 in Group B underwent periodic examinations over a similar time period (5.2 years, range 3.3–7.4 years and 5.4 years, range 3.4–7.5 years, respectively). Median sodium-lithium countertransport activity was stable when evaluated after 2 and 4 years of follow-up. Only seven patients were excluded from the protocol because changes in their sodium-lithium countertransport activity placed them on the other side of the median value with respect to their baseline measurement. Thus, 152 patients completed the study (76 in Group A and 76 in Group B). Of the 76 patients in Group A, 17 developed persistent microalbuminuria (22.3 %). The number of patients in Group B showing persistent microalbuminuria was significantly lower (4 of 76; 5.2 %; p < 0.01). The sensitivity of erythrocyte Na ⁺ /Li ⁺ CT in predicting the development of microalbuminuria was 85 % and its specificity was 55 %. Seven patients of Group A and five of Group B developed arterial hypertension. Subjects in Group A had significantly higher mean HbA_{1 c} values of twice yearly measurements than those in Group B (9.6 ± 1.7 vs 8.3 ± 1.7 %, p < 0.002, mean ± SD) despite similar daily insulin requirements. Systolic and diastolic blood pressure levels were also evaluated every 6 months and were significantly higher in the Group A than in the Group B patients, although on average within the normal range. The odds ratio for developing persistent microalbuminuria in IDDM with elevated baseline erythrocyte Na ⁺ /Li ⁺ CT activity after adjustment for gender and baseline albumin excretion rate, and mean 6 monthly plasma creatinine, HbA_{1 c} and systolic and diastolic blood pressure levels was 4.2 (95 % confidence intervals 2.0–11.1). It was also found that the percentage of offspring having both parents with Na ⁺ /Li ⁺ CT activity above the median value was significantly higher in Group A than in Group B (Group A vs Group B: 35 vs 19 %; p < 0.01). On the contrary the percentage of offspring whose erythrocyte Na ⁺ /Li ⁺ CT was lower in both parents was lower in Group A than in Group B: 10 vs 38 %, p < 0.01). Parents of Group A offspring had arterial hypertension more frequently than those of Group B. These results indicate that erythrocyte Na ⁺ /Li ⁺ CT activity is a useful diagnostic tool in identifying normotensive, normoalbuminuric patients who may be predisposed to develop persistent microalbuminuria. This disorder in the cation transport system is associated with poor metabolic control, higher blood pressure, and male sex; it also appears to be, at least partly, genetically transmitted. [Diabetologia (1997) 40: 654–661] Received: 10 September 1996 and in final revised form: 20 February 1997     

The relationship of urinary albumin excretion rate to ambulatory blood pressure and erythrocyte sodium-lithium countertransport in NIDDM

Summary Increased erythrocyte sodium-lithium countertransport rate is found in non-diabetic subjects with essential hypertension, and in insulin-dependent diabetic subjects with nephropathy. However, relationships between these variables in non-insulin-dependent diabetic subjects are ill-defined. In order to characterise the relationships between blood pressure, urinary albumin excretion, and erythrocyte sodium-lithium countertransport, 66 subjects with non-insulin-dependent diabetes were studied. Urinary albumin excretion rate correlated with mean 24-h ambulatory systolic blood pressure (r=0.57; p<0.001), but not with sodium-lithium countertransport (r=0.06; p=0.31). No significant relationship was observed between 24-h systolic blood pressure and erythrocyte sodium-lithium countertransport (r = 0.16; p=0.17). The principal differences between microalbuminuric and normoalbuminuric subjects (albumin excretion rate >15 g·min^–1 [n=20], and <15 g·min^–1, [n=46]) were: higher 24-h systolic blood pressure (145.9 [16.8] mm Hg vs 131.9 [16.8] mm Hg; p=0.006), nocturnal heart rate (72.4 [8.9] vs 67.4 [8.9] beats·min^–1; p=0.042), and HbA₁ (11.3 [1.5]% vs 10.1 [2.0]%; p=0.028), and a longer median duration of diabetes (10.0 vs 5.0 years; p = 0.02). In contrast, there was no significant difference in sodium-lithium countertransport rate between microalbuminuric (0.41 [0.18] mmol·l^–1·h^–1) and normoalbuminuric subjects (0.39 [0.15] mmol·l^–1· h^–1; p=0.687). In multiple regression analysis controlling for race, age, body mass index and HbA₁, the significant determinants of albumin excretion rate were 24-h systolic blood pressure (B [regression coefficient]=0.029, SE[B] [standard error of B]=0.009, t=2.95, p=0.005), duration of diabetes (B=0.430, SE[B]=0.169, t=2.54, p=0.016) and male gender (B=–1.170, SE[B]=0.457, t=–2.56, p=0.015). In conclusion, albumin excretion rates in non-insulin-dependent diabetic subjects are linked to hypertension and glycaemic exposure, but show no relationship to erythrocyte sodium-lithium countertransport.Abbreviations IDDM Insulin-dependent diabetes mellitus - NIDDM non-insulin dependent diabetes mellitus - SLC sodium lithium countertransport - AER albumin excretion rate - B regression - SE coefficient; standard error of B     

Erythrocyte Sodium - Lithium Countertransport in Chinese: Its Relationship to Family History of Hypertension

Rates of sodium (Na⁺) - stimulated lithium (Li ⁺) efflux (Na⁺-Li⁺ countertransport) and ouabain-sensitive Na⁺ efflux (Na⁺ pump) were determined in erythrocytes of Chinese normotensive and hypertensive subjects. Near-maximal rate of Na⁺ - Li⁺ countertransport was found to be significantly higher in hypertensive than normotensive subjects. No significant difference was observed for the rate of Na⁺ pump between them. A second series of study involved normotensive subjects without and with hypertensive parent(s) (group A and B, respectively) and hypertensive subjects (group C). We found that the rate of Na⁺ - Li⁺ countertransport in group A was significantly lower than that of group B and C, while no difference existed between group B and C. No significant difference was observed for the rate of Na⁺ pump among the three groups. Our results suggested that Na⁺-Li⁺ countertransport activity could be a genetic marker for essential hypertension in Chinese, similar to that as proposed in Caucasians.     

Na+-K+ Cotransport and Hypertension. Effect of Piretanide and Hydrochlorothiazide on Red Blood Cell Sodium Concentration in Acutely Salt-Loaded Hypertensive and Normotensive Rats

Na⁺-K⁺ cotransport has been presumed to be a genetic marker or aetiological factor in essential hypertension in numerous studies. In spite of extended in vitro research, the role of this transport system in hypertension could not be proved. In the pressent study the action of the cotransport inhibitor piretanide and the non-loop diuretic hydrochlorothiazide (HCT) on red blood cell (RBC) sodium concentration was examined under in vivo conditions in spontaneously hypertensive rats (SHR) and normotensive Sprague Dawley rats (NSDR) during acute salt-loading.

Before drug administration salt-loading resulted in an increase of RBC sodium concentration, the percentage of which was not different in SHR and NSDR. However, after administration of piretanide in oral doses of 8–32 mg/kg body weight, the percent increase in RBC sodium was lower in SHR than in NSDR. This effect which was found to be dose-dependent was not brought about by HCT.

The data might be due to a piretanide inhibition of sodium-induced inward RBC Na⁺-K⁺ cotransport more pronounced in SHR than in NSDR.     

Relationship between sodium–lithium countertransport and insulin sensitivity in mild hypertension

Objectives. To study the relationship between insulin sensitivity and sodium-lithium countertransport (Na⁺-Li⁺ CT) in mild, essential hypertension, and to investigate the effect of metformin and metoprolol, respectively. Design. A double-blind, triple cross-over, placebo-controlled study over a total period of 18 weeks. Setting. A hypertension out-patient clinic and research laboratory at Sahlgrenska University Hospital. Subjects. Seventeen non-obese men with mild essential hypertension and 17 weight-matched, healthy controls. Interventions. Metformin 850 mg b.i.d., metoprolol CR 100 mg once daily and placebo were given during 18 weeks. Each treatment period was 6 weeks. A euglycaemic clamp was performed and erythrocyte Na⁺-Li⁺ CT measured after each 6-week treatment period. Main outcome measures. Insulin sensitivity, erythrocyte Na⁺-Li⁺ CT, their interrelation, and the effect of metformin and metoprolol CR on both variables, respectively. Results. The hypertensive men tended to have an elevated Na⁺-Li⁺ CT compared with the control subjects (0.34±0.03 versus 0.26±0.02 mmol L^-1  h^-1, P<0.1). Glucose disposal rate was similar, but plasma insulin levels higher (P<0.05) among the hypertensives than the controls. Na⁺-Li⁺ CT exhibited a positive relationship to BMI (r=0.53, P=0.03) and a negative correlation to glucose disposal rate (r=-0.66, P=0.008) in the hypertensive subjects. In multiple regression analysis, Na⁺-Li⁺ CT showed a significant correlation to glucose disposal rate only. In the control subjects, there was no relation between glucose metabolism and Na⁺-Li⁺ CT. Neither metformin nor metoprolol influenced Na⁺-Li⁺ CT, glucose disposal rate or plasma insulin. Conclusion. Erythrocyte Na⁺-Li⁺ CT seemed to be closely related to insulin-glucose metabolism in mild hypertension, but was not influenced by metformin or metoprolol.     

Impaired response to angiotensin II in Type 1 (insulin-dependent) diabetes mellitus. Role of prostaglandins and sodium-lithium countertransport activity

Summary The pathogenesis of diabetic nephropathy remains elusive. A role for renal prostaglandins in antagonizing the hormonal effects of renin-angiotensin II has been postulated as a putative factor leading to hyperfiltration in patients with Type 1 (insulin-dependent) diabetes mellitus. Our aim was to elucidate the effects of angiotensin II on kidney haemodynamics and on blood pressure in eight normal subjects, in nine normotensive, in nine hypertensive with normal sodium-lithium countertransport activity in erythrocytes, in seven hypertensive without and in eight hypertensive Type 1 diabetic patients with microalbuminuria and with high sodium-lithium countertransport activity in erythrocytes. Angiotensin II infusion 4ng·kg^–1·min^–1 for 60 min) decreased the glomerular filtration rate to a greater extent in normal subjects (–20%), than in normotensive patients (–5% p<0.01), in hypertensive patients with normal sodium-lithium countertransport activity in erythrocytes (–8% p<0.01) in hypertensive patients with high sodium-lithium countertransport (–6% p<0.01) and in hypertensive microalbuminuric patients (–5% p<0.01) with Type 1 diabetes. The urinary excretion rate of vasodilatory prostaglandins was two-three fold higher in all patients than in normal subjects. Acute indomethacin treatment restored a normal response to angiotensin II infusion in normotensive patients, but did not change the renal haemodynamic response in normal subjects. With regard to hypertensive patients with and without microalbuminuria indomethacin treatment restored a normal response to angiotensin II in some but not all patients. An inverse relation was found between angiotensin II-induced decrease in the glomerular filtration rate and the sodium-lithium countertransport activity in erythrocytes during indomethacin treatment. Hypertensive and microalbuminuric patients with a sodium-lithium countertransport activity higher than 0.41 mmol·l erythrocyte^–1·h^–1 (the upper limit in normal subjects) also had a greater intimal plus medial thickness of the carotid artery using an ultrasonic imaging technique. Chronic indomethacin administration (30 days) significantly decreased the baseline overnight fasting glomerular filtration rate in normotensive and in hypertensive patients with normal but not in hypertensive and microalbuminuric patients with high sodium-lithium countertransport activity.In conclusion these results demonstrate that: (1) excessive synthesis of vasodilatory prostaglandins antagonizes the regulation of renal haemodynamics by angiotensin II, at least partially accounting for hyperfiltration in Type 1 diabetes, (2) elevated sodium-lithium countertransport activity in erythrocytes identifies a subgroup of patients with Type 1 diabetes and hypertension, with and without microalbuminuria, in whom the normalization of urinary excretion rate of prostaglandins does not restore a normal response to angiotensin II.     

老年高血压病病人血糖水平与动态脉压相关性探讨

目的探讨老年原发性高血压病人血糖水平与动态脉压的相关性。方法对455例老年高血压病（EH）病人进行体检，检测空腹血糖（FBG）、餐后2h（2hBG）血糖及其他指标，比较不同血糖水平组间脉压大小。结果老年高血压病病人血糖水平与脉压密切相关，3组间比较有统计学意义（P〈0．01）。年龄、收缩压、舒张压、2hBG与PP有显著相关性（r分别为0．108、0．111、0．097、0．777，P〈0．001）。结论合并糖尿病的老年高血压病病人应加强脉压的监控。     

Typology of Na+ transport abnormalities in erythrocytes from essential hypertensive patients. A first step towards the diagnosis and specific treatment of different forms of primary hypertension

Over the last 5 years, several authors have measured apparent affinities and maximal translocation rates of the different erythrocyte Na⁺ transport systems in essential hypertensive patients. These kinetic studies have clearly shown that no unique red cell Na⁺ transport defect characterizes the whole population of essential hypertensive patients. Conversely,several complex patterns of erythrocyte Na⁺ transport abnormalities may be present in different subsets of essential hypertensive patients. These kinetic studies are now providing a more profound biochemical insight into the molecular heterogeneity of primary hypertension. In particular, they may permit the diagnosis and specific treatment of different forms of primary hypertension in the next decade.     

高血压患者血浆一氧化氮含量与动态血压的关系

目的探讨原发性高血压患者血浆一氧化氮含量变化及其与２４小时动态血压值的相关性。方法５８例原发性高血压患者，平均年龄６０．２±１１．７岁，男性３０例，女性２８例，用比色法测定血浆硝酸根含量，并用２４小时动态血压仪测量动态血压。结果高血压患者血浆硝酸根含量（１．２１±０．４３ｎｍｏｌ／ｍｌ）明显低于正常人（１．４６±０．２３ｎｍｏｌ／ｍｌ），并与疾病的严重程度相平行，相关分析显示血浆硝酸根含量与２４小时动态血压值呈负相关。结论一氧化氮在高血压病的发生、发展中起着重要的作用     

老年原发性高血压患者心脑血管事件与动态血压的关系

目的 :探讨动态血压及偶测血压与高血压预后的关系。　　方法 :随访的 12 9例老年原发性高血压患者入选时分别测量基础状态下动态血压及诊室血压 ,并根据白昼舒张压水平分为高、中、低、3组 (HL组 36例、ML组 5 1例、L L组 42例 ) ,然后在平均 38个月随访观察与原发性高血压相关的心脑血管事件。　　结果 :12 9例中发生心、脑、肾各类事件者 2 2例。单因素分析表明事件患者各项动态血压参数明显高于非事件患者(P<0 .0 5～ 0 .0 1) ,而两者诊室血压间无显著差异 (P>0 .0 5 )。L L、ML、HL 3组中事件发生率分别为 2例 / 10 0人年、5 .1例 / 10 0人年及 9.5例 / 10 0人年。多因素分析显示 :收缩压节律、夜间收缩压水平及总胆固醇水平为高血压患者事件发生的独立危险因素 ,分别为 RR=3.0 5、RR=1.2 7、RR=1.48(P<0 .0 5～ 0 .0 1)。　　结论 :动态血压在判断高血压预后方面较诊室血压更具有临床意义 ,较高的动态血压水平 (白昼舒张压水平 )提示不良的预后 ,收缩压节律、夜间收缩压水平是预测高血压患者心脑血管事件及肾脏受损的独立危险因素。     

Hereditary Hypertriglyceridemic Rat: A New Animal Model of Metabolic Alterations in Hypertension

Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na⁺ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension.     

高血压患者左室肥厚及主动脉根内径与动态血压的关系

目的探讨ＡＢＰ与左室后壁厚度（ＬＶＰＷＴ），室间膈厚度（ＩＶＳＴ）及主动脉内径（ＡＯＤ）之间的联系。方法对８８例原发性高血压患者应用超声心动图及动态血压计同时测定其ＬＶＰＷＴ、ＩＶＳＴ、ＡＯＤ及动态血压各参数值。结果左室肥厚（ＬＶＰＷＴ或／和ＩＶＳ）者５０例，主动脉根扩张者６０例。相关分析显示ＬＶＰＷＴ、ＬＶＳＴ及ＡＯＤ、动态血压各参数平均值呈显著正相关（Ｐ＜０．０５），其中与２４ｈ平均收缩压、最高收缩压及夜间平均收缩压相关最密切（Ｐ＜０．０１），此外ＬＶＰＷＴ，ＩＶＳＴ及ＡＯＤ与２４ｈ最高收缩压与最低收缩压之差（ΔＡＢＰｓ）及２４ｈ最高舒张压与最低舒张压之差（ΔＡＢＰｓ）亦呈正相关（Ｐ＜０．０５），其中与ΔＡＢＰｓ相比更密切（Ｐ＜０．０１）。结论血压波动性是左室肥厚及主动脉根内径的影响因素。     

Prevalence and Clinical Profile of Resistant Hypertension among Treated Hypertensive Subjects

We assessed prevalence and clinical characteristics of resistant hypertension (RH) and prevalence of false RH (white-coat effect [WCE] by home blood pressure [BP] monitoring), among a population of 302 treated hypertensive patients, mean age 66.6 (±13.8), 67.5% women. Resistant hypertension was defined according to the American Heart Association criteria. Prevalence of RH was 10%, and the following five variables were independently associated with it: body mass index, diabetes, isolated systolic hypertension, orthostatic hypotension, and use of beta-blockers. Prevalence of WCE among subjects with office-RH was 27.6%. Our study identified easily measurable parameters related to RH. Standing BP should be systematically measured in individuals with RH.     

原发性高血压血压昼夜节律与运动血压的关系

目的 :探讨原发性高血压患者血压昼夜节律与运动血压的关系。方法 :检测 30 3例 1、2级原发性高血压患者的运动血压和动态血压 ,根据夜间血压下降率不同分为杓型组 (n =2 0 0 )和非杓型组 (n =10 3) ,比较两组运动血压各参数 ,并行相关分析。结果 :①非杓型组最大运动量时收缩压、舒张压和运动后恢复期收缩压、舒张压均高于杓型组 ,有极显著性差异(P <0 .0 1或 0 .0 0 1)。②夜间收缩压下降率与最大运动量时收缩压、舒张压存在明显负相关 (γ =-0 40 7、-0 361,P均<0 .0 0 1) ;夜间舒张压下降率与最大运动量时收缩压、舒张压、运动后恢复期收缩压存在明显负相关 (γ =-0 499、-0 479、-0 183,P均 <0 0 1或 0 0 0 1)。结论 :非杓型原发性高血压患者容易出现运动血压过度升高     

The Relationship Between Neutrophil Lymphocyte Ratio and Non-dipper Hypertension

Non-dipper hypertension is associated with increased cardiovascular morbidity and mortality. Neutrophil/lymphocyte ratio (NLR) has been associated with poor outcomes in patients with cardiovascular diseases. However, little is known about the role of NLR in patients with non-dipper hypertension. In this study, NLR between dipper and non-dipper hypertensive patients was compared.This study included 80 hypertensive patients. Hypertensive patients were divided into two groups: 50 dipper patients (29 male, mean age 51.5 ± 8 years) and 30 non-dipper patients (17 male, mean age 50.6 ± 5.4 years). Transthoracic echocardiography and ambulatory 24-hour blood pressure monitoring were performed on all patients. No patient had a recent history of an acute infection or an inflammatory disease. Baseline NLR was measured by dividing neutrophil count to lymphocyte count. No statistically significant difference was found between the two groups in terms of basic characteristics. Mean NLR was significantly higher among persons with non-dipper compared with dipper patients (3.1 ± 0.95 vs. 1.8 ± 0.52, P < .001). Additionally, leukocytes and monocytes counts were higher in patients with non-dipper hypertension.In conclusion, our results suggest that higher NLR, an emerging marker of inflammation, has a positive correlation with blood pressure and is elevated in non-dippers compared with dippers.     

盐敏感性高血压病患者的胰岛素抗性与应激血压反应特点

目的观察盐敏感者胰岛素抗性与应激血压反应的关系。方法对３３例高血压病患者和２７例血压正常对照者用静脉盐水负荷和速尿缩容相结合的方法确定盐敏感性（ＳＳ）基础上，进行糖耐量、胰岛素释放试验；精神激发，冷加压和运动等试验。结果ＳＳ与盐不敏感者（ＳＲ）比较，空腹及糖负荷后各时点血糖及胰岛素含量均明显增高，胰岛素敏感指数降低（Ｐ均＜０．０５）；空腹血胰岛素在百分位Ｐ７５以上者或胰岛素敏感指数在百分位Ｐ２５以下者，精神激发及冷加压后平均动脉压上升幅度（ΔＭＡＰ）明显增加，且与空腹血胰岛素水平呈正相关（ｒ值分别为０．３８１及０．４２３，Ｐ＜０．０５），与胰岛素敏感指数呈负相关（ｒ值为－０．３９３和－０．２６７，Ｐ＜０．０５）。结论盐敏感者有胰岛素抗性增加的表现，且与应激血压明显增强相关联     

Investigation of Major Genetic Polymorphisms in the Renin-Angiotensin-Aldosterone System in Subjects with Young-Onset Hypertension Selected by a Targeted-Screening System at University

Although polymorphisms in renin-angiotensin-aldosterone (RAA) system genes for angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE I/D), angiotensin II type 1 receptor (AT1 A/C¹¹⁶⁶), and aldosterone synthase (CYP11B2–344T/C) have been major targets for genetic investigation in association with essential hypertension (EH), the influence of these genetic factors is still to be determined. Because patients with young-onset EH are thought to possess a stronger genetic background than EH patients who show elevated BP relatively late in life, the targeted screening of hypertensive students in Tohoku University was completed for the selection of subjects for genetic investigation. Out of 16,434 students (12,794 males and 3,670 females) younger than 30, 22 students showed a high blood pressure (BP) (systolic and diastolic BP of 140 and/or 90 mmHg or greater, respectively, on two occasions and more than 135 and/or 85 mmHg, respectively, at a third measurement during casual BP measurements at the Tohoku University Health Center. These 22 students were asked to measure their BP at home (HBP). Six of the students had a systolic HBP of more than 135 mmHg and/or a diastolic HBP of more than 85 mmHg, and these students subsequently received medical examinations at Tohoku University Hospital and were diagnosed with EH. Genotyping for the four major genetic polymorphisms mentioned above was performed on the six students with EH and on 12 of the remaining 16 students whose HBP was within the normal range (white coat hypertension: WCH). Neither the EH nor the WCH students showed a different distribution of genotypes and allelic frequencies, compared to those found in the general Japanese population. Hence, the present study suggests that none of the major genetic polymorphisms in the RAA system strongly influence the onset of EH.     

The Relationship of Plasma Ionized Calcium to Cardiovascular Disease Endpoint and Family History of Hypertension

Plasma ionized calcium and total calcium were measured on 271 individuals from 34 Utah pedigrees divided into groups defined by the method of pedigree ascertainment: 1) hypertension clusters, 2) early stroke death clusters and 3) clusters of early heart attack deaths. Normotensive individuals were also categorized by family history of hypertension. Members of stroke cluster pedigrees had higher mean plasma ionized Ca²⁺ than either hypertension pedigrees (p < 0.05) or coronary artery disease pedigrees which had the lowest concentrations (p < 0.001). Within the normotensive group, those subjects with a positive family history of hypertension exhibited significantly higher plasma ionized Ca²⁺ (2.18 ± 0.10 (S.D.) mEq/1) than individuals without a family history of hypertension (2.12 ± 0.08 mEq/1, p < 0.01). In medicated hypertensives, both ionized (p < 0.05) and total (p < 0.01) plasma calcium were higher than calcium levels in the normotensive negative family history subjects. Plasma ionized Ca²⁺ in the adult normotensives (N=134) had significant age corrected positive correlations with plasma sodium (r = 0.25, p < 0.01), potassium (r=0.29, p<0.001) and erythrocyte sodium-lithium countertransport values (r=0.20, p<0.05). These findings provide additional evidence that plasma ionized calcium concentrations may be important to help define the heterogeneity of hypertension in adult Americans.     

动态血压昼夜节律改变与高血压并发症

用无创性动态血压监测（ＡＢＰＭ）仪观察１４２例高血压（ＥＨ）患者２４ｈ动态血压，显示血压昼夜节律消失的６２例中，ＥＨ并发症者５０例，占８０．６％，无并发症者１２例，占１９．４％；在５０例ＥＨ并发症且血压昼夜节律消失的患者中，脑卒中２８例，占５６．０％；在３６例脑卒中患者中，血压昼夜节律消失２８例，占７７．８％。提示血压昼夜节律消失较多见于高血压有并发症者，尤其是脑卒中者。