Metabolic neutrality of combined verapamil-trandolapril treatment in contrast to beta-blocker-low-dose chlortalidone treatment in hypertensive type 2 diabetes.

OBJECTIVE: To investigate the metabolic, antihypertensive and albuminuria-modifying effects of a heart rate-modulating calcium antagonist-angiotensin converting enzyme inhibitor combination compared with those of a beta-blocker-low-dose diuretic combination in non-insulin-dependent diabetic hypertensives. DESIGN: A prospective randomized double-blind study. SUBJECTS AND METHODS: Twenty-four diabetics with diastolic blood pressure 90-115 mmHg without azotemia (plasma creatinine level < 150 mumol/l) were evaluated after 4 weeks receiving placebo and 12 weeks receiving treatment either with combined slow-release verapamil (retard formulation) and trandolapril (mean maintenance doses, 180 and 1.6 mg daily) or with atenolol and chlortalidone (71 and 18 mg daily). Insulin sensitivity (by the minimal model method of Bergman), additional metabolic variables, clinic blood pressure, ambulatory blood pressure profile and renal indices were assessed at the end of the placebo and active treatment phases. RESULTS: Compared with placebo, the two therapies produced similar decreases in mean supine clinic blood pressure [10 +/- 3 versus 11 +/- 3% (means +/- SEM)], upright clinic blood pressure (10 +/- 4 versus 11 +/- 4%) and ambulatory daytime blood pressure (9 +/- 2 versus 12 +/- 3%). However, although the verapamil-trandolapril combination was found to be metabolically neutral, the atenolol-chlortalidone combination aggravated insulin resistance [insulin sensitivity index, from (0.8 +/- 0.2) to (0.3 +/- 0.1) x 10(-4)/min per U per ml], increased the serum triglycerides level and decreased the high-density lipoprotein cholesterol and plasma potassium levels. Although both therapies tended to reduce 24 h albuminuria, this was significant for the verapamil-trandolapril treatment only. CONCLUSIONS: Because the effect of any antihypertensive drug, including diuretics and beta-blockers, on cardiovascular morbidity and on mortality in non-insulin-dependent diabetic patients is not known, rational treatment selection can presently be based only on surrogate end-points. Therefore, the triad of metabolic neutrality with antihypertensive and antiproteinuric efficacy supports combined verapamil-trandolapril as a potentially valuable therapy for hypertension accompanying diabetes mellitus.

Sample modulated Raman spectroscopy and frequency modulated visible light--resonance Raman spectrum of a polydiacetylene fiber.

Methods for obtaining sample modulated Raman (SMR) spectra and frequency modulated visible light are described. The sample modulated Raman method is one in which the frequency of the Raman scattered light is modulated by the sample which is responding to an externally applied periodic stress. The Raman active modes of the sample which are due to the vibrational motion of those molecular-scale units that change in response to the external stress are modulated and appear in the frequency-locked phase sensitively detected Raman spectrum. Those modes due to units that do not respond significantly to the stress do not appear. In principle the SMR method permits determination of those molecular units of a complex substance that are responsible for the substance's response to an external stress. The Raman scattered light is frequency modulated, has the wave form nu=nu(0)-nu(i)-(deltanu) sin(2pi ft), where nu(0) is the incident monochromatic light, nu(i) is the vibrational frequency of the statically stressed material, and (deltanu) is the magnitude of the frequency shift caused by the maximum stress applied at the frequency f.