We determined in 5 control subjects and in one patient with total congenital lipoatrophy (LA) the effect of
insulin infusion on
glucose flux and some aspects of lipid metabolism. In the post-absorptive state LA had moderate
hyperglycemia (9.2 versus 3.80 +/- 0.07 mmol.l-1) and
hyperinsulinemia (19 vs 12 +/- 3 mU.l-1) and a massive increase in
glucose production (7.51 mg.kg.-1.min-1) and disappearance (7.40 mg.kg-1.min-1) rates (control subjects: 2.29 +/- 0.14 mg.kg-1 min-1). Raising peripheral
insulin levels to 28 +/- 3 mU.l-1 suppressed endogenous
glucose production in the control subjects whereas in LA significant (2.01 mg.kg-1.min-1) production persisted even when peripheral insulinemia was raised to 58 mU.l-1.
Insulin infusion in control subjects increased progressively
glucose utilization to a final value of 15.7 +/- 0.7 mg.kg-1.min-1 (corresponding plasma
insulin: 482 +/- 44 mU.l-1).
Insulin infusion in LA initially lowered
glucose level near to normal values and exogenous
glucose was infused for an
insulin infusion rate of 10 mU.kg-1.min-1; at this
insulin infusion rate
glucose utilization rate (6.52 mg.kg-1.min-1) was decreased relative to control subjects in spite of higher
insulin levels (750 mU.l-1).
NEFA,
glycerol and
ketone bodies (KB) levels were decreased to undetectable levels by
insulin infusion in the normal subjects whereas
NEFA and
glycerol were decreased only in part and KB were not modified in LA. In addition
glycerol and KB appearance rates determined in LA were not suppressed by
insulin infusion as expected.(ABSTRACT TRUNCATED AT 250 WORDS)