Lipid Profile During Antihypertensive Treatment - SLIP


SLIP is a multi-center, prospective trial of the effect of Verapamil sustained release 240 mg daily and Enalapril 20 mg daily on plasma lipid levels among patients with mild or moderate hypertension.


Treatment with Verapamil sustained release or Enalapril, alone or in combination, will improve plasma lipid levels among patients with mild or moderate hypertension.

Study Design

Study Design:

Patients Enrolled: 931
Mean Follow Up: 6 months
Mean Patient Age: Mean of 56 years
Female: 50

Patient Populations:

  • Outpatients with mild to moderate essential hypertension
  • Supine diastolic blood pressure between 95 and 115 mm Hg at the end of a 3-week washout period


  • Age over 70 years
  • Severe or complicated hypertension
  • Recent myocardial infarction
  • Bradycardia (<50 beats/minute)
  • Second or third degree AV block
  • NYHA Grade II-IV heart failure
  • Cerebrovascular event within 3 months
  • Diabetes Mellitus
  • Severe dyslipidemia
  • Hepatic or renal failure
  • Severe comorbidity
  • History of hypersensitivity to calcium channel blockers or ACE inhibitors

Primary Endpoints:

  • Systolic and diastolic blood pressure before and 6 months after treatment
  • Plasma lipid levels before and 6 months after treatment

Secondary Endpoints:

  • Heart rate before and after treatment
  • Body weight before and after treatment
  • Electrocardiographic changes before and after treatment
  • Change in blood glucose and uric acid levels before and after treatment

Drug/Procedures Used:

  • Verapamil sustained release (SR) 240 mg daily for 6 months
  • Enalapril 20 mg daily for 6 months
    • A drug washout period of 3 weeks was required prior to intervention

      Concomitant Medications:

      After at least 1 month of monotherapy, a second antihypertensive medication could be added if the diatolic blood pressure remained >95 mm Hg.
      • Enalapril 20 mg daily was added if the patient had been taking Verapamil
      • Hydrochlorothiazide 12.5 mg daily was added if patients were receiving Enalapril
      If a combination regimen was initiated, it was continued throughout the study period

Principal Findings:

  • There was a significant reduction (9.5% and 9.8%) in systolic blood pressure before and 1 month after treatment in the Verapamil and Enalapril groups, respectively (p<0.01)
  • There was a significant association with improvement in total cholesterol (-7.2% vs. -3.7%), triglycerides (-8.5% vs. -6.3%), and LDL (-8.4% vs. -5.0%) with Verapamil and Enalapril, respectively (p<0.01)
  • HDL levels were significantly increased in the Verapamil (p<0.01) but not significantly greater in the Enalapril group
  • Increase in HDL levels was significantly associated with the use of Verapamil compared with Enalapril +9.5% vs. +2.5%, respectively (p<0.01)


Among patients age less than 70 years with mild or moderate hypertension without additional cardiac risk factors, treatment with Verapamil SR 240 mg and Enalapril 20 mg daily were both associated with a significant reduction in systolic and diastolic blood pressure and with a reduction in triglycerides, total and LDL cholesterol before and 6 months after treatment. Verapamil was further associated with a significant increase in HDL levels compared with Enalapril.


Libretti A, et al. Lipid Profile During Antihypertensive Treatment: The SLIP Study. Drugs 1993; 46:16-23.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Heart Failure and Cardiomyopathies, Prevention, Homozygous Familial Hypercholesterolemia, Hypertriglyceridemia, Lipid Metabolism, Nonstatins, Hypertension

Keywords: Enalapril, Cholesterol, LDL, Hyperlipidemias, Risk Factors, Verapamil, Hypercholesterolemia, Triglycerides, Hypertension, Systole, Calcium Channel Blockers

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