Copeptin, a surrogate marker for arginine vasopressin secretion, is positively associated with glucagon

To explore the association of plasma copeptin, the C-terminal portion of provasopressin and a stable surrogate marker for arginine vasopressin secretion, with plasma glucagon in obese men and men of normal weight.

We measured fasting blood concentrations of copeptin and glucagon in 102 healthy obese men (mean ± sd age 49.4 ± 10.2 years) and a control group 27 healthy men of normal weight (mean ± sd age 51.5 ± 8.4 years). Differences between groups were evaluated using t-tests, and multiple linear regression analysis, adjusting for age and weight status (normal weight vs obese), was used to calculate unstandardized regression coefficients (β) with 95% CIs between copeptin and glucagon. Copeptin was (natural) log-transformed.

The obese men had higher [median (interquartile range)] plasma copeptin concentrations [6.6 (4.6-9.5) vs 4.9 (3.5-6.8) pmol/l; P = 0.040] and higher mean ± sd plasma glucagon concentrations (8.5 ± 3.8 vs 5.3 ± 1.4 pmol/l; P < 0.001) than the normal-weight men. Adjusted for age and weight status, copeptin was significantly associated with glucagon (β = 1.35, 95% CI 0.13-2.57; P = 0.031). No significant interaction effect between copeptin and weight status on glucagon was found (P = 0.81).

Obese men had higher concentrations of copeptin and glucagon than men of normal weight. Copeptin was positively associated with glucagon. Our data suggest that increased arginine vasopressin-stimulated glucagon secretion might contribute to higher glucagon concentrations; therefore, increased arginine vasopressin secretion, in addition to other factors, could further aggravate the hyperglucagonaemic state found in obese individuals.