title: The ratio of leptin to adiponectin can be used as an index of insulin resistance.
abstract: The level of leptin increases with obesity, whereas that of adiponectin decreases with obesity. It is reported that the ratio of leptin to adiponectin (L/A) is associated with insulin resistance. It is difficult to evaluate insulin resistance in diabetic patients who have a dysfunction of insulin secretion. The aim of this study was to examine whether the L/A ratio is a useful marker for insulin resistance in diabetic patients. We examined L/A in the serum of a total of 139 Japanese patients with type 2 diabetes mellitus (66 women and 73 men) and 7 healthy individuals recruited in our hospital. Changes in the levels of leptin and adiponectin were observed using the oral glucose tolerance test and a hyper- and euglycemic clamp test. Twenty-one patients with type 2 diabetes mellitus were observed for more than 6 months after treatment with pioglitazone, and 31 patients with type 2 diabetes mellitus were observed for more than 6 months after the treatment with metformin. The mean value of L/A in 139 Japanese patients with type 2 diabetes mellitus was 1.22 +/- 1.41 (1.68 +/- 1.76 in women, 0.81 +/- 0.80 in men; P = .0002). In the clamp tests, L/A correlated with glucose infusion rate (GIR) (r(2) = 0.26, P = .0034). The correlation of L/A and GIR indicated a stronger correlation than either leptin (r(2) = 0.144, P = .03) or adiponectin alone (r(2) = 0.023, P = .41), or the homeostasis model assessment of insulin resistance (r(2) = 0.103, P = .08). The average hemoglobin A(1c) (HbA(1c)) improved from 10.2% +/- 1.2% to 9.2% +/- 1.6% (P = .0037) in 6 months after treatment with pioglitazone. Our results indicate pioglitazone to be effective for HbA(1c) improvement in subjects with high L/A and low L/A. The average HbA(1c) improved from 9.2% +/- 0.9% to 8.0% +/- 1.2% (P = .0002) in 6 months after treatment with metformin. Our results indicate metformin to be effective for HbA(1c) improvement in subjects with a low L/A. In conclusion, we demonstrate that L/A is different between male and female subjects. The correlation of L/A and GIR by the euglycemic hyperinsulinemic clamp test suggests that L/A is a useful indicator for the choice of drug to treat diabetes mellitus.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Oda
authors.forename: Shigeo
authors.initials: S
authors.lastname: Imamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujita
authors.forename: Yuka
authors.initials: Y
authors.lastname: Uchida
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Inagaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kakizawa
authors.forename: Nobuki
authors.initials: N
authors.lastname: Hayakawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Jun
authors.initials: J
authors.lastname: Takeda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Horikawa
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Itoh
mesh_terms: D052242:Adiponectin / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000097:blood*; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D000077205:Pioglitazone; D045162:Thiazolidinediones / Q000627:therapeutic use
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D020738:Leptin; D008687:Metformin; D000077205:Pioglitazone; D045162:Thiazolidinediones