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Alteration of melatonin secretion in patients with type 2 diabetes and proliferative diabetic retinopathy.

Hikichi T, Tateda N, Miura T - Clin Ophthalmol (2011)

Bottom Line: Nighttime melatonin levels were significantly lower in the diabetic group than in the nondiabetic group (P < 0.03) and lower in the PDR group than in the nondiabetic and NPDR groups (P < 0.01 and P < 0.03, respectively), but no significant difference was found between the nondiabetic and NPDR groups.The daytime melatonin level did not significantly differ between the nondiabetic and diabetic groups or between the nondiabetic, NPDR, and PDR groups.Alteration of melatonin secretion may accelerate further occurrence of complications in diabetic patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Ohtsuka Eye Hospital, Sapporo, Japan. taiichi-hikichi@hokkaido.med.or.jp

ABSTRACT

Background: The purpose of this study was to evaluate the dynamics of plasma melatonin secretion in patients with type 2 diabetes mellitus and diabetic retinopathy.

Methods: Plasma melatonin levels were measured by high-performance liquid chromatography in 56 patients. Patients were divided into a diabetic group (30 patients) and a nondiabetic group (26 patients). The diabetic group was divided further into a proliferative diabetic retinopathy (PDR) group (n = 14) and a nonproliferative diabetic retinopathy (NPDR) group (n = 16). Plasma melatonin levels obtained at midnight and 3 am were compared between the groups.

Results: Nighttime melatonin levels were significantly lower in the diabetic group than in the nondiabetic group (P < 0.03) and lower in the PDR group than in the nondiabetic and NPDR groups (P < 0.01 and P < 0.03, respectively), but no significant difference was found between the nondiabetic and NPDR groups. The daytime melatonin level did not significantly differ between the nondiabetic and diabetic groups or between the nondiabetic, NPDR, and PDR groups.

Conclusion: The nighttime melatonin level is altered in patients with diabetes and PDR but not in diabetic patients without PDR. Although patients with PDR may have various dysfunctions that affect melatonin secretion more severely, advanced dysfunction of retinal light perception may cause altered melatonin secretion. Alteration of melatonin secretion may accelerate further occurrence of complications in diabetic patients.

No MeSH data available.


Related in: MedlinePlus

Typical circadian fluctuations in plasma melatonin from five nondiabetic volunteers. The plasma concentration of melatonin reached its highest level at around midnight and lowest at around 3 pm. Vertical lines are one standard error of the means.
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f1-opth-5-655: Typical circadian fluctuations in plasma melatonin from five nondiabetic volunteers. The plasma concentration of melatonin reached its highest level at around midnight and lowest at around 3 pm. Vertical lines are one standard error of the means.

Mentions: Circadian fluctuations in melatonin were assessed by drawing blood in dim light (0 lux) via an indwelling cannula from an antecubital vein for measurement of melatonin levels at midnight and 12.30 am while the patients were sleeping, and in the afternoon between 3 pm and 3.30 pm. Particular attention was paid to allowing the participants to remain asleep during the midnight blood collection. Blood samples were obtained from all patients 2 days after surgery. Plasma melatonin was measured by high-performance liquid chromatography in all patients. This method has proven reproducibility and can detect a 0.5 pg/mL plasma concentration of melatonin, which is a lower value than that of the lowest circadian level of melatonin. Our preliminary study showed that the plasma concentration of melatonin obtained from five nondiabetic volunteers peaked at around midnight and was lowest at around 3 pm (Figure 1).


Alteration of melatonin secretion in patients with type 2 diabetes and proliferative diabetic retinopathy.

Hikichi T, Tateda N, Miura T - Clin Ophthalmol (2011)

Typical circadian fluctuations in plasma melatonin from five nondiabetic volunteers. The plasma concentration of melatonin reached its highest level at around midnight and lowest at around 3 pm. Vertical lines are one standard error of the means.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104794&req=5

f1-opth-5-655: Typical circadian fluctuations in plasma melatonin from five nondiabetic volunteers. The plasma concentration of melatonin reached its highest level at around midnight and lowest at around 3 pm. Vertical lines are one standard error of the means.
Mentions: Circadian fluctuations in melatonin were assessed by drawing blood in dim light (0 lux) via an indwelling cannula from an antecubital vein for measurement of melatonin levels at midnight and 12.30 am while the patients were sleeping, and in the afternoon between 3 pm and 3.30 pm. Particular attention was paid to allowing the participants to remain asleep during the midnight blood collection. Blood samples were obtained from all patients 2 days after surgery. Plasma melatonin was measured by high-performance liquid chromatography in all patients. This method has proven reproducibility and can detect a 0.5 pg/mL plasma concentration of melatonin, which is a lower value than that of the lowest circadian level of melatonin. Our preliminary study showed that the plasma concentration of melatonin obtained from five nondiabetic volunteers peaked at around midnight and was lowest at around 3 pm (Figure 1).

Bottom Line: Nighttime melatonin levels were significantly lower in the diabetic group than in the nondiabetic group (P < 0.03) and lower in the PDR group than in the nondiabetic and NPDR groups (P < 0.01 and P < 0.03, respectively), but no significant difference was found between the nondiabetic and NPDR groups.The daytime melatonin level did not significantly differ between the nondiabetic and diabetic groups or between the nondiabetic, NPDR, and PDR groups.Alteration of melatonin secretion may accelerate further occurrence of complications in diabetic patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Ohtsuka Eye Hospital, Sapporo, Japan. taiichi-hikichi@hokkaido.med.or.jp

ABSTRACT

Background: The purpose of this study was to evaluate the dynamics of plasma melatonin secretion in patients with type 2 diabetes mellitus and diabetic retinopathy.

Methods: Plasma melatonin levels were measured by high-performance liquid chromatography in 56 patients. Patients were divided into a diabetic group (30 patients) and a nondiabetic group (26 patients). The diabetic group was divided further into a proliferative diabetic retinopathy (PDR) group (n = 14) and a nonproliferative diabetic retinopathy (NPDR) group (n = 16). Plasma melatonin levels obtained at midnight and 3 am were compared between the groups.

Results: Nighttime melatonin levels were significantly lower in the diabetic group than in the nondiabetic group (P < 0.03) and lower in the PDR group than in the nondiabetic and NPDR groups (P < 0.01 and P < 0.03, respectively), but no significant difference was found between the nondiabetic and NPDR groups. The daytime melatonin level did not significantly differ between the nondiabetic and diabetic groups or between the nondiabetic, NPDR, and PDR groups.

Conclusion: The nighttime melatonin level is altered in patients with diabetes and PDR but not in diabetic patients without PDR. Although patients with PDR may have various dysfunctions that affect melatonin secretion more severely, advanced dysfunction of retinal light perception may cause altered melatonin secretion. Alteration of melatonin secretion may accelerate further occurrence of complications in diabetic patients.

No MeSH data available.


Related in: MedlinePlus