Morningness-eveningness questionnaire score correlates with glycated hemoglobin in middle-aged male workers with type 2 diabetes mellitus.
OBJECTIVE
'Morningness' and 'eveningness' represent the sleep-wake patterns of the circadian rhythm might also affect glycemic control in patients with type 2 diabetes. The aim of this study was to examine the relationship between the morningness-eveningness trait and metabolic parameters.


METHODS
The study participants comprised 101 Japanese male workers with type 2 diabetes treated in an outpatient clinic. Blood samples were obtained, and a morningness-eveningness questionnaire (MEQ), where a high score represents morningness; and the Pittsburg Sleep Quality Index (PSQI), where the higher the score the worse the sleep quality, were carried out.


RESULTS
MEQ correlated positively with age, and high-density lipoprotein cholesterol (HDL-C), and negatively with glycated hemoglobin (HbA1c) and PSQI. Multivariate regression analysis showed that MEQ was significantly associated with HbA1c and HDL-C. In addition, we classified the study patients into three groups: 'morning type', 'neither type' and 'evening type' according to the sum of the MEQ score, and analyzed the difference between morning type (n = 32) and evening type (n = 11). We found that HbA1c, low-density lipoprotein cholesterol and PSQI of the morning type group were significantly lower than those of the evening type group.


CONCLUSIONS
The present study suggests that 'eveningness' type male Japanese workers with type 2 diabetes suffer inadequate glycemic control.
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Masato
M
Iwasaki
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Takahisa
T
Hirose
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan ; Center for Molecular Diabetology Juntendo University Graduate School of Medicine Tokyo Japan.
Tomoya
T
Mita
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Fumihiko
F
Sato
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Chiharu
C
Ito
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Risako
R
Yamamoto
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Yuki
Y
Someya
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Tomoaki
T
Yoshihara
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan ; Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan.
Yoshifumi
Y
Tamura
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan.
Akio
A
Kanazawa
Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan.
Ryuzo
R
Kawamori
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan ; Center for Beta-Cell Biology and Regeneration Juntendo University Graduate School of Medicine Tokyo Japan.
Yoshio
Y
Fujitani
Department of Metabolism & Endocrinology Juntendo University Graduate School of Medicine Tokyo Japan ; Center for Molecular Diabetology Juntendo University Graduate School of Medicine Tokyo Japan ; Sportology Center Juntendo University Graduate School of Medicine Tokyo Japan ; Center for Beta-Cell Biology and Regeneration Juntendo University Graduate School of Medicine Tokyo Japan ; Center for Therapeutic Innovations in Diabetes Juntendo University Graduate School of Medicine Tokyo Japan.
Hirotaka
H
Watada
Japanese; Morningness–eveningness questionnaire; Type 2 diabetes mellitus