We will evaluate the combination of quinapril and alpha lipoic acid in patients with diabetes mellitus and hypertension. We will determine whether the combination of quinapril and lipoic acid as compared to quinapril and placebo provides benefit on systemic blood pressure and proteinuria.

The participant will be randomized to either quinapril 40 mg and alpha lipoic acid versus quinapril 40 mg and placebo for 8 weeks. There will be a wash out period of 4 weeks between the cross over. The participant will be assigned the cross over for 8 weeks on the opposite therapy.

Inclusion Criteria:

Patients who have a diagnosis of diabetes mellitus as defined by fasting blood glucose levels greater than ot equal to 126mg/dL and a systolic BP greater than 125 mm Hg at the time of screening will be included in the study. Patients may be on antihypertensive medication but not on ACE inhibitor or ARB therapy at the time of enrollment.

Exclusion Criteria:

Systolic blood pressure > 180 mmHg Creatinine > 2.5 mg/dl Glycosylated hemoglobin > 7.5% Congestive heart failure (NYHA Class II, III or IV) Coronary angiography planned prior to baseline sampling Chronic autoimmune disease Chronic inflammatory disease or known cancer in evolution life expectancy < 1 year Immunosuppressives or treatment with any other investigational drug within the last 30 days Pregnant or nursing women Participants who experience any side effects to quinapril and/or alpha lipoic acid

Women of childbearing potential Women of childbearing potential enrolled in the study should use one of the acceptable methods of birth control as listed below

1. Abstinence, meaning a total lack of any sexual activity.
2. Oral contraceptives (the "pill"),
3. Contraceptive injections,
4. Intrauterine device,
5. Double-barrier method (diaphragm or condom + spermicidal cream),
6. Contraceptive patch, or
7. Male partner sterilization.

Pregnancy Any pregnancy that occurs during study participation must be reported to the Principal Investigator and the study coordinator at the earliest. The pregnancy must be followed up to determine outcome and status of the mother and child. To ensure subject safety, any subject that becomes pregnant during the study will be discontinued from the trial.