Fumihiko Kamezaki

Seasonal variation in metabolic syndrome prevalence

Accumulating evidence has shown that seasonal variations can exist within metabolic syndrome parameters. The aim of this study was to examine the hypothesis that there are seasonal variations in the prevalence of metabolic syndrome in Japanese subjects. We investigated a total of 1202 male workers in our institution (44±10 years) who underwent health checkups in both June (summer) and December (winter) 2008. In this study, metabolic syndrome was defined according to the criteria proposed by the National Cholesterol Education Program (NCEP), the International Diabetes Federation (IDF) and the Japanese Society of Internal Medicine (JSIM). Serum levels of high-density lipoprotein-cholesterol and fasting glucose, as well as blood pressure (BP), were significantly higher in winter than in summer, whereas waist circumference and serum levels of triglyceride exhibited little change. The prevalence rates of NCEP, IDF, and JSIM metabolic syndrome in this study were 3.8, 15.1 and 12.4% in winter and 3.2, 10.7 and 8.4% in summer, respectively. Of all metabolic syndrome components, an elevated BP was most significantly correlated with the seasonal variation of metabolic syndrome prevalence. This study demonstrated seasonal variations in metabolic syndrome prevalence in Japanese male workers. These results indicate that the season of health checkups may affect the clinical diagnosis and management of metabolic syndrome.

Serum soluble lectin-like oxidized low-density lipoprotein receptor-1 correlates with oxidative stress markers in stable coronary artery disease.

BACKGROUND Although serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) is reported to be associated with acute coronary syndrome (ACS), its correlation with oxidative stress markers has not been elucidated. We therefore investigated the association of serum sLOX-1 with the severity of CAD, and serum biomarkers for oxidative stress and inflammation, as well as extracellular superoxide dismutase (EC-SOD), which is protective against oxidative stress in the vascular wall. METHODS AND RESULTS Ninety-four patients with stable CAD were enrolled in this study. Serum sLOX-1, serum high-sensitivity C-reactive protein (hs-CRP), urinary 8-isoprostane, plasma BNP and serum lipid levels were measured. We also measured EC-SOD at baseline and post-heparin injection. Heparin-released EC-SOD (DeltaEC-SOD) was calculated as the difference between these two values. No significant correlation was found between log (sLOX-1) and log (basal EC-SOD) (p=0.096), log (hs-CRP) (p=0.108), or log (BNP) (p=0.908) levels, log (sLOX-1) had a significant correlation with DeltaEC-SOD (r=-0.325, p=0.0014) levels and urinary 8-isoprostane levels (r=0.243, p=0.020). In the multivariable analysis, DeltaEC-SOD (p=0.0177) and 8-isoprostane (p=0.0318) were independent predictors for log (sLOX-1). CONCLUSION Serum sLOX-1 levels were positively correlated with urinary 8-isoprostane levels and inversely correlated with EC-SOD levels. These results thus suggest that increased serum sLOX-1 levels may reflect enhanced oxidative stress in vascular walls.

Angiotensin receptor blocker improves coronary flow velocity reserve in hypertensive patients: comparison with calcium channel blocker.

Large-scale clinical studies have indicated that angiotensin receptor blockers (ARBs) have beneficial effects against cardiovascular diseases. We designed this study to compare the effects of an ARB and a calcium channel blocker (CCB) on coronary flow velocity reserve (CFVR), a predictor of cardiovascular events, as estimated using transthoracic Doppler echocardiography. Sixteen hypertensive patients (63.1±9.6 years old; 10 males) were randomly allocated in a double-blind fashion to valsartan (n=8, 40–80 mg/day) or nifedipine (n=8, 20–40 mg/day) groups. Age- and gender-matched subjects without hypertension were enrolled as a control group (n=12). CFVR was calculated by dividing the adenosine triphosphate–induced hyperemic flow velocity by the basal flow velocity in the left anterior descending coronary artery. Baseline characteristics and reduction in systolic and diastolic blood pressure after 6 months were similar in both groups. CFVR in the valsartan group increased from 2.34±0.38 to 3.10±0.84 at 2 months (p<0.05), and to 3.04±1.09 at 6 months (p<0.01). Both values became comparable to that in the control group (2.81±0.60). CFVR in the valsartan group was significantly higher (p<0.001) than that in the nifedipine group, which was little changed at 6 months. This discrepancy was derived from the significant increase of hyperemic velocity in the valsartan group, from 36.6±17.3 cm/s to 41.1±12.7 cm/s at 2 months, and to 48.1±20.2 cm/s at 6 months. We concluded that the ARB valsartan not only reduced high blood pressure but improved CFVR in hypertensive patients. However, these effects were not seen with the CCB nifedipine.

Association of seasonal variation in the prevalence of metabolic syndrome with insulin resistance

The aim of this study was to examine the hypothesis that seasonal variation in the prevalence of metabolic syndrome (MetS) is associated with increased insulin resistance. Among 840 Japanese male workers who were evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR) in June (summer) 2010, we prospectively studied a total of 758 subjects (40–65 years of age) who underwent an assessment in December (winter) 2010. MetS was defined according to the criteria proposed by the International Diabetes Federation (IDF) and the Japanese Society of Internal Medicine (JSIM). The median level of HOMA-IR in the study subjects was 0.84 (interquartile range: 0.60–1.19). The prevalence rates of IDF- and JSIM-MetS significantly increased from 12.4 and 9.6% in the summer to 16.6 and 13.3% in the winter, respectively (each P<0.05). Our data suggest that these increases are mainly due to increases in blood pressure (BP) and glucose during the winter assessment. The prevalence rates of IDF-MetS in the first, second, third and fourth quartiles of HOMA-IR were 1.1, 5.8, 14.3 and 29.1% in the summer and 3.1, 10.6, 21.9, and 31.3% in the winter, respectively. Similar results were obtained when using the JSIM criteria. In the third quartile, the frequency of elevated BP increased from 42.4% in the summer to 61.2% in the winter (P<0.05), and these values were mainly correlated with significant variations in IDF- and JSIM-MetS prevalence rates. This study demonstrates that seasonal variation in MetS prevalence is associated with mildly to moderately increased insulin resistance in middle-aged Japanese men.

Plasma Levels of Nitric Oxide Metabolites Are Markedly Reduced in Normotensive Men With Electrocardiographically Determined Left Ventricular Hypertrophy

Recent studies have revealed that electrocardiographically determined left ventricular hypertrophy (ECG-LVH) is a risk factor for cardiovascular death not only in hypertensive patients but also in normotensive subjects. However, the underlying mechanisms remain to be elucidated. In this study, we tested our hypothesis that normotensive subjects with ECG-LVH have reduced nitric oxide production. A total of 840 Japanese male workers were enrolled, and 579 eligible subjects were studied. ECG-LVH was assessed according to the Sokolow–Lyon voltage criteria and the Cornell voltage–duration product. The median level of plasma NOx (nitrite plus nitrate), a marker of systemic nitric oxide production, was markedly lower in the normotensive subjects with ECG-LVH (n=73) than in those without (n=506), and the clinical characteristics were significantly different between the 2 groups (each P<0.05). Importantly, a one-to-one propensity score matching analysis showed similar markedly lower median plasma NOx level in the normotensive subjects with ECG-LVH compared with that observed in the matched normotensive subjects without ECG-LVH (P<0.05). Furthermore, the tertiles of the plasma NOx levels were inversely correlated with the prevalence and severity of ECG-LVH (both P<0.05). The lower plasma NOx levels were associated with significantly higher plasma 8-isoprostane levels, a marker of systemic lipid peroxidation (P<0.05). These results provide the first evidence that normotensive subjects with ECG-LVH exhibit defective nitric oxide production, along with increased oxidative stress. Our findings may thus explain, at least in part, a potential mechanism underlying the increased risk of cardiovascular death in normotensive individuals with ECG-LVH.

Percutaneous stenting of bilateral central venous occlusions in a hemodialysis patient.

Upper-extremity central venous obstruction is often first recognized when an arteriovenous fistula is made for hemodialysis at an ipsilateral site. We encountered a case of markedly expanded edema after making an arteriovenous fistula in the left forearm. Systemic venography showed that the bilateral brachiocephalic veins and right subclavian vein were occluded. Implantation of a self-expandable stent in the left brachiocephalic vein relieved the edema. However, recurrence of similar edema and occlusion of the left brachiocephalic vein were noted after 1.5 years. The left brachiocephalic vein was then recanalized by ballooning and additional stent implantation, and a stent was implanted between the superior vena cava and right subclavian vein. Simultaneous reconstruction of the bilateral central venous obstruction by percutaneous intervention rather than surgical repair was suitable for this patient because of previous thoracoplasty. We also believe that this method can provide an opportunity to select the suitable forearm for making an arteriovenous fistula, in which the ipsilateral central vein will exhibit little restenosis.

CORONARY ARTERIAL REMODELING AND PERISTENT PLAQUE CHANGE AFTER DRUG-ELUTING STENT IMPLANTATION – COMPARISON BETWEEN ZOTAROLIMUS-ELUTING STENTS AND PACLITAXEL-ELUTING STENTS -

BACKGROUND Out-stent plaque characteristics and eosinophilic inflammatory response, which correlates with positive remodeling after first-generation drug-eluting stent implantation, may be associated with late restenosis and very late stent thrombosis. The differences of out-stent plaque characteristics were compared between paclitaxel-eluting stents (PES) and zotarolimus-eluting stents (ZES), using integrated backscatter-intravascular ultrasound (IB-IVUS). METHODS AND RESULTS Of 78 patients enrolled, 25 receiving PES and 25 receiving ZES had adequate IVUS assessment. Volumetric IVUS analysis was performed after stenting and at 8-month follow-up. Out-stent plaque change in the stented segment was compared on IB-IVUS. The relationship between systemic inflammatory response and out-stent plaque change was evaluated. In PES, vessel volume significantly increased (365-389 mm(3), P<0.0001), whereas it did not change in ZES (315-314 mm(3), P=0.81). In culprit lesions at baseline in PES, fibrous plaque tended to increase (3.1-3.6mm(2), P=0.051) and lipid plaque significantly increased (4.3-5.1mm(2), P=0.02), whereas in ZES the fibrous plaque significantly increased (2.9-4.0mm(2), P<0.0001) but lipid plaque significantly decreased (5.1-3.6mm(2), P<0.0001). Systemic eosinophil increase was significantly correlated with positive remodeling and out-stent lipid plaque increase. CONCLUSIONS Chronic out-stent plaque change in ZES consisted of less positive remodeling and more favorable effects on out-stent plaque characteristics than PES. Systemic eosinophil change might be a marker of out-stent lipid plaque change.

Press‐through package mis‐swallowing: Usefulness of computed tomography

An 88‐year‐old female with Alzheimers‐type dementia who mis‐swallowed a press‐through package visited our emergency department.

Successful coronary intervention for spontaneous coronary dissection in a patient with fibromuscular dysplasia

Spontaneous coronary artery dissection (SCAD) is a reported rare cause of acute coronary syndrome (ACS) and sudden death among middle-aged women. Some institutes have recently reported fibromuscular dysplasia (FMD) concomitant with SCAD. Therefore, a survey of the presence of comorbid FMD in SCAD patients is important to obtain a definitive diagnosis and for the prediction of possible SCAD recurrence. The optimal treatment of ACS due to SCAD remains undetermined, and technical failures are frequently encountered in primary percutaneous coronary intervention (PCI) owing to the unusual non-atherosclerotic cause of the disease. We report a case of SCAD successfully treated with cutting balloon PCI under intravascular ultrasound guidance without stent implantation, in which FMD was detected in the right external iliac artery through screening by noncoronary angiography, not duplex ultrasound. <Learning objective: SCAD is a rare cause of ACS. Intravascular ultrasound is helpful to avoid the technical failures associated with primary percutaneous coronary intervention in the treatment of ACS due to SCAD. FMD has been recently reported to be concomitant with SCAD. Therefore, this report aimed to survey the presence of comorbid FMD in SCAD patients given its important role in obtaining a definitive diagnosis and predicting the possible recurrence of SCAD.>.

A rare case of myocardial infarction related to diagnostic intravascular ultrasound

A 71-year-old man underwent intracoronary stent implantation for acute inferior myocardial infarction (MI). Immediately after diagnostic intravascular ultrasound (IVUS) at 8 months’ follow-up, an acute occlusion of the sinus node (SN) artery appeared, which developed sinus arrest with junctional escape rhythm. The serum level of high-sensitivity troponin T (TpT) was markedly elevated on the day after the procedure (2.1–32.5 ng/l), which was indicative of MI related to IVUS. Under continuous intravenous infusion of unfractionated heparin, the escape rhythm changed to lower atrial rhythm on the 4th day, and recovered to sinus rhythm on the 14th day. Coronary angiography (CAG) on 15th day showed a recanalization of the SN artery, but optical coherence tomography identified that disrupted plaque and white thrombus still existed in the ostium of the SN artery. The patient was discharged on maintenance anticoagulation therapy. We hypothesized from this case that IVUS-related myocardial injury may exist without clinical problems. Our retrospective investigation showed that the median levels of high-sensitivity TpT in 20 patients who underwent CAG and subsequent diagnostic IVUS significantly increased from 0.6 (interquartile range 0.3–1.1) to 1.6 (0.7–3.6) ng/l (P < 0.05), suggesting that IVUS may induce very low levels of myocardial injury. In conclusion, we experienced a rare case of IVUS-related MI caused by an acute occlusion of the SN artery. This case reaffirms that we should pay more attention to manipulation of IVUS catheters.