81915
document
The effect of metformin and insulin on sympathetic nerve activity , norepinephrine spillover and blood pressure in obese , insulin resistant , normoglycemic , hypertensive men . To evaluate the effect of metformin on insulin sensitivity and to further examine the relationship between insulin resistance , sympathetic nerve activity and blood pressure , 6 obese insulin resistant , normoglycemic hypertensive men were investigated ( age 49 +/- 2 years , BMI 27.6 +/- 1.2 , mean +/- SEM ) . The study had a placebo controlled , double blind , cross over design with 6 weeks ' metformin treatment ( 850 mg b.i.d ) vs placebo . Blood pressure was measured weekly . At the end of each treatment period , glucose infusion rate ( GIR ) , muscle sympathetic nerve activity ( MSA ) and renal and total body norepinephrine ( NE ) kinetics ( radioisotope dilution ) were examined during euglycemic hyperinsulinemic clamp . Fasting insulin was 13 +/- 3 and 10 +/- 2 mU/l and fasting glucose 5.3 +/- 0.2 and 5.1 +/- 0.1 mmol/l after placebo and metformin treatment , respectively ( ns ) . GIR during the last hour of the insulin clamp was 3.7 +/- 0.6 vs 3.6 +/- 0.6 mg/kg x min ( ns ) . Resting MSA , total body and right renal NE spillover did not differ significantly after placebo and metformin treatment . Systolic and diastolic blood pressures were 151 +/- 10/95 +/- 5 mmHg after placebo and 146 +/- 5/94 +/- 5 mmHg after metformin treatment ( ns ) . Thus metformin treatment did not have any significant effect on insulin sensitivity , blood pressure or sympathetic activity in this small group of patients . Renal plasma flow and MSA increased significantly during the insulin clamp , whereas renal NE and total body NE spillover remained unchanged , suggesting nonuniform regional sympathetic nerve responses to acute hyperinsulinemia .
81916
Intervention_Pharmacological
metformin
81917
Intervention_Pharmacological
insulin
81918
Intervention_Pharmacological
metformin
81919
Intervention_Control
placebo
81920
Intervention_Pharmacological
metformin
81921
Intervention_Control
placebo
81922
Intervention_Pharmacological
metformin
81923
Intervention_Pharmacological
metformin
81924
Outcome_Physical
Blood pressure
81925
Outcome_Physical
glucose infusion rate ( GIR )
81926
Outcome_Physical
muscle sympathetic nerve activity ( MSA )
81927
Outcome_Physical
renal and total body norepinephrine ( NE ) kinetics ( radioisotope dilution )
81928
Outcome_Physical
Fasting insulin
81929
Outcome_Physical
Resting MSA
81930
Outcome_Physical
total body and right renal NE spillover
81931
Outcome_Physical
Systolic and diastolic blood pressures
81932
Outcome_Physical
blood pressure
81933
Outcome_Physical
sympathetic activity
81934
Participant_Condition
obese
81935
Participant_Condition
insulin resistant
81936
Participant_Condition
normoglycemic
81937
Participant_Condition
hypertensive
81938
Participant_Sample-size
6
81939
Participant_Condition
obese insulin resistant
81940
Participant_Condition
normoglycemic hypertensive
81941
Participant_Sex
men
81942
Participant_Age
49 +/- 2