Long-term prognostic implications of metabolic syndrome in heart transplant recipients.

BACKGROUND: Metabolic syndrome (MS) increases the risk of cardiovascular events due to endothelial dysfunction. There are few studies evaluating the impact of MS on the survival of heart transplantation (HTx) patients. AIM: The aim of this study was to study the impact of MS in the early period and on the long-term survival after HTx. MATERIALS AND METHODS: We studied 196 HTx patients with a minimum survival of 1 year post-HTx. A diagnosis of MS was made at 3 months after HTx, if at least 3 of the following criteria were met: triglyceride levels ≥150 mg/dL (or drug treatment for hypertriglyceridemia); high-density lipoprotein cholesterol (HDL-C) <40 mg/dL in men and <50 mg/dL in women (or drug treatment to raise HDL-C levels); diabetes mellitus on drug treatment or fasting glucose levels ≥100 mg/dL; blood pressure ≥130/85 mm Hg (or on antihypertensive drug treatment); and body mass index (BMI) ≥30. We used the Kaplan-Meier method (log-rank test) to calculate long-term survival and Student t and chi-square tests for comparisons. RESULTS: Among 196 patients, 96 developed MS. There were no differences between the groups with versus without MS in recipient gender, underlying etiology, smoking, pre-HTx diabetes, or immunosuppressive regimen. However, differences were observed between groups in age (MS: 53 ± 9 vs non-MS: 50 ± 12 years; P = .001); pre-HTx creatinine (MS: 1.2 ± 0.3 vs non-MS: 1.0 ± 0.4 mg/dL; P = .001); BMI (MS: 27.3 ± 4 vs non-MS: 24.6 ± 4; P = .001); pre-HTx hypertension (MS: 48% vs non-MS: 17%; P < .001); and dyslipidemia (MS: 53% vs non-MS: 37%; P = .023). Long-term survival was better among the non-MS group, but the difference did not reach significance (MS: 2381 ± 110 vs non-MS: 2900 ± 110 days; P = .34). CONCLUSIONS: The development of MS early after HTx is a common complication that affects nearly 50% of HTx patients. The prognostic implication of this syndrome on overall survival might occur in the long term.

Determination of the Atmospheric-Water-Vapor Content in the 940-nm Absorption Band by Use of Moderate Spectral-Resolution Measurements of Direct Solar Irradiance.

We have analyzed three methods that can be used to determine the integrated water vapor of the atmosphere in the 940-nm band by means of modeled and measured direct solar spectral irradiance. The experimental irradiance data were obtained with a commercial LI-COR 1800 spectroradiometer, based on a monochromator system, of high to moderate spectral resolution (6 nm) in the 300-1100-nm range. The modeled data are based on monochromatic approaches to determine atmospheric transmittance constituents; for those of water vapor we used the lowtran7 model. The first method is a curve-fitting procedure that makes use of the entire shape band absorption information to retrieve a unique water-vapor value. The second method makes use of the monochromatic approach of the absorption transmittance formula to determine the amount of water vapor at each wavelength of the absorption band, and the third method is the classic differential absorption technique suitably applied to our data. Spectral analysis showed the advantages and disadvantages of each method, such as problems linked to the various spectral resolutions of the experimental and the modeled data, the width of the spectral range used to define the water-vapor absorption band, and the dependence of the retrieval on the choice of the two selected wavelengths in the last-named technique. All these problems were considered so they could be avoided or minimized and the associated errors estimated. We used the methods to determine water-vapor values for the period from March to November 1995 at a rural station in Vallodolid, Spain, allowing for the evaluation of the differences in real monitoring conditions. Finally, the contribution of continuum absorption was also evaluated, yielding lower water-vapor values between 13 and 30%. These differences were considerably greater than those that were due to the problems that we have just enumerated.