Cardiovascular effects of a novel SIRT1 activator, SRT2104, in otherwise healthy cigarette smokers

BACKGROUND

We examined the effect of the oral SIRT1 activator SRT2104 on cardiovascular function in otherwise healthy cigarette smokers.

METHODS AND RESULTS

Twenty-four otherwise healthy cigarette smokers participated in a randomized double-blind, placebo-controlled crossover trial and received 28 days of oral SRT2104 (2.0 g/day) or matched placebo. Plasma SRT2104 concentrations, serum lipid profile, plasma fibrinolytic factors, and markers of platelet and monocyte activation were measured at baseline and at the end of each treatment period together with an assessment of forearm blood flow during intra-arterial bradykinin, acetylcholine, and sodium nitroprusside infusions. Three hours postdose, mean plasma SRT2104 concentration was 1328 ± 748 ng/mL after 28 days of active treatment. Compared with placebo, serum lipid profile improved during SRT2104 administration, with reductions in serum total cholesterol (-11.6 ± 20 versus 6 ± 21 mg/dL), low-density lipoprotein cholesterol (-10 ± 17 versus 3 ± 21 mg/dL), and triglyceride (-39.8 ± 77 versus 13.3 ± 57 mg/dL) concentrations (P<0.05 for all). All vasodilators produced a dose-dependent increase in blood flow (P<0.0001) that was similar during each treatment period (P>0.05 for all). No significant differences in fibrinolytic or blood flow parameters were observed between placebo and SRT2014.

CONCLUSIONS

SRT2104 appears to be safe and well tolerated and associated with an improved lipid profile without demonstrable differences in vascular or platelet function in otherwise healthy cigarette smokers.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT01031108.

A complicated pregnancy in a patient with lipodystrophic diabetes attributable to a peroxisome proliferator-activated receptor gamma (PPARG) mutation

BACKGROUND

We describe an unplanned pregnancy in a 19-year-old with lipodystrophic diabetes caused by a mutation in the peroxisome proliferator-activated receptor gamma (PPARG) gene. The pregnancy was complicated by poor compliance with treatment, severe hypertriglyceridaemia and pancreatitis.

CASE REPORT

The patient presented at 6 weeks' gestation with an HbA(1c) of 140 mmol/mol (15%), cholesterol 8.1 mmol/l and triglycerides 20.1 mmol/l. She wished to continue the pregnancy so lipid-lowering therapy was discontinued. She was severely insulin resistant and poorly compliant with diet and medication. A continuous subcutaneous insulin infusion was required for efficient delivery of large doses of basal insulin, alongside injected mealtime boluses, (up to 300 units insulin per day). At 17 weeks' gestation she developed acute pancreatitis secondary to hypertriglyceridaemia (triglycerides > 100 mmol/l) and required plasmapheresis. Lipid-lowering therapy was reinstated in the third trimester and plasmapheresis was required repeatedly to maintain triglycerides < 10 mmol/l. Delivery was arranged at 32 weeks, because of deteriorating glycaemic and lipid control (blood pressure was normal). Following betamethasone for fetal lung maturation, 20 units/h of intravenous insulin were required to maintain glycaemic control. A baby boy with significant subsequent developmental delay was delivered.

DISCUSSION

The features of PPARG mutations are discussed, with literature on lipodystrophy and pancreatitis in pregnancy reviewed. There are few documented cases of pregnancy in women with PPARG mutations. The notable features of this case include the consequences of non-concordance with treatment, the use of continuous subcutaneous insulin infusion to treat insulin-resistant diabetes and the need for repeated plasmapheresis during pregnancy to avert pancreatitis.