Wee Hyun Park

Incidence of Hypertension in Korea: 5-Year Follow-up Study

Limited data are available about the incidence of hypertension over the 5-yr in non-hypertensive subjects. The study subjects were 1,806 subjects enrolled in a rural area of Daegu, Korea for a cohort study from August to November 2003. Of them, 1,287 (71.3%) individuals had another examination 5 yr later. To estimate the incidence of hypertension, 730 non-hypertensive individuals (265 males; mean age = 56.6 ± 11.1 yr-old) at baseline examination were analyzed in this study. Hypertension was defined as either a new diagnosis of hypertension or self-reports of newly initiated antihypertensive treatment; prehypertension was if the systolic blood pressure was 120-139 mmHg and/or diastolic blood pressure was 80-89 mmHg. During the 5-yr follow-up, 195 (26.7%) non-hypertensive individuals developed incident hypertension. The age-adjusted 5-yr incidence rates of hypertension were 22.9% (95% confidence interval [CI] = 19.9-29.0) in overall subjects, 22.2% (95% CI = 17.2-27.2) in men, and 24.3% (95% CI = 20.4-28.2) in women. The incidence rates of hypertension significantly increased with age. In the multivariate analysis, prehypertension (Odds ratio [OR] 2.25; P < 0.001) and older age (OR 2.26; P = 0.010) were independent predictors for incident hypertension. In this rapidly aging society, population-based preventive approach to decrease blood pressure, particularly in subjects with prehypertension, is needed to reduce hypertension.

A ROLE FOR RHO-KINASE IN Ca2+-INDEPENDENT CONTRACTIONS INDUCED BY PHORBOL-12,13-DIBUTYRATE

1 Phorbol‐12,13‐dibutyrate (PDBu) is an activator of protein kinase C (PKC) that causes contractions in both physiological salt solutions and Ca2+‐depleted solutions. In the present study, we tested the hypothesis that Rho‐kinase plays a role in Ca2+‐independent contractions induced by PDBu in vascular smooth muscles. 2 In Ca2+‐free solution, 0.1 and 1 µmol/L PDBu induced contraction and myosin light chain (MLC20) phosphorylation, both of which were approximately 40% of responses obtained in normal Krebs’ solution. Hydroxyfasudil (H1152; 1 µmol/L), an inhibitor of Rho‐kinase, but not ML7 (10 µmol/L), an inhibitor of myosin light chain kinase, inhibited Ca2+‐independent contractions induced by PDBu. 3 In Ca2+‐free solution, PDBu increased phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and CPI‐17 (PKC‐potentiated inhibitory protein for heterotrimeric myosin light chain phosphatase of 17 kDa). This action was inhibited by H1152, with the phosphorylation of CPI‐17 almost completely abolished by 1 µmol/L Ro31‐8220, an inhibitor of PKC. 4 In Ca2+‐free solution, PDBu increased the amount of GTP‐RhoA (an activated form of RhoA). This increase was blocked by the PKC inhibitor Ro31‐8220, but not by the Rho kinase inhibitor H1152. 5 In conclusion, RhoA/Rho‐kinase plays an important role in Ca2+‐independent contractions induced by PDBu in vascular smooth muscles. The results of the present study suggest that PDBu induces Ca2+‐independent contractions by inhibiting myosin light chain phospatase (MLCP) through activation of GTP‐RhoA and subsequent phosphorylation of MYPT1 and CPI‐17.

HEAT SHOCK‐INDUCED AUGMENTATION OF VASCULAR CONTRACTILITY IS INDEPENDENT OF RHO‐KINASE

1 In a previous study, we demonstrated that heat shock augments the contractility of vascular smooth muscle through the stress response. 2 In the present study, we investigated whether Rho‐kinases play a role in heat shock‐induced augmentation of vascular contractility in rat isolated aorta. 3 Rat aortic strips were mounted in organ baths, exposed to 42C for 45 min and subjected to contractile or relaxant agents 5 h later. 4 The level of expression of Rho‐kinases in heat shock‐exposed tissues was no different to that of control tissues, whereas heat shock induced heat shock protein (Hsp) 72 at 3 and 5 h. Heat shock resulted in an increase in vascular contractility in response to phenylephrine 5 h later. 5 The Rho‐kinase inhibitors Y27632 (30 nmol/L‐10 mmol/L) or HA 1077 (10 nmol/L‐10 mmol/L) relaxed 1.0 mmol/L phenylephrine‐precontracted vascular strips in a concentration‐dependent manner; these effects were attenuated in heat shock‐exposed strips. Pretreatment with Y27632 resulted in greater inhibition of the maximum contraction in control strips compared with those in heat shock‐exposed strips. 6 The results of the present study suggest that Rho‐kinases are unlikely to be involved in heat shock‐induced augmentation of vascular contractility.

Recurrent Catecholamine-Induced Cardiomyopathy in a Patient With a Pheochromocytoma

Pheochromocytomas presents with variable clinical manifestations. Cardiomyopathy caused by a pheochromocytoma is well known. We report the case of a 62-year-old woman with recurrent left ventricular dysfunction, who was subsequently found to have a pheochromocytoma. The patient had two different patterns of cardiomyopathy. Patients with a cardiomyopathy, of non-specific origin, should have a pheochromocytoma ruled out.

Prevalence of Diabetes Mellitus and Prediabetes in Dalseong-gun, Daegu City, Korea

Background The aim of the present study was to determine the population-based prevalence of diabetes mellitus (DM) and prediabetes in a rural district of Daegu City, Korea. Methods Between August and November 2003, a community-based health survey of adults aged 20 years and older was performed in the rural district of Dalseong-gun in Daegu City. A total of 1,806 of all eligible individuals agreed to participate. Fasting plasma glucose was measured in all participants. Two hour oral glucose tolerance was measured in the 1,773 participants for whom there was neither an established diagnosis of DM nor evidence of DM according to fasting glucose levels. The prevalence of DM and prediabetes was determined according to the 2003 criteria of the American Diabetes Association. Subjects with prediabetes were classified into one of three categories of glucose intolerance: isolated impaired fasting glucose (IFG); isolated impaired glucose tolerance (IGT); or combined IFG and IGT. Results The prevalence of DM was 12.2%. The highest prevalence rates were observed in subjects in their seventies. A total of 34.7% of all subjects who were assigned a diagnosis of DM in the present study had not been diagnosed previously. The prevalence of prediabetes was 22.7%. The highest prevalence rates were observed in subjects in their fifties. Conclusion The present study identified prevalence rates of 12.2% for DM (age-standardized prevalence rate [ASR], 6.8%), and 22.7% for prediabetes (ASR 18.5%). These results emphasize the need for community health promotion strategies to prevent or delay the onset of DM in individuals with prediabetes.

Thallium-201 uptake in keloid tissue masquerading as a pulmonary neoplasm.

TI-201 imaging is useful in the diagnostic work-up of tumors. However, TI-201 uptake is not specific for tumor and is also noted in other conditions. A case is described in which TI-201 was taken up by a keloid.