睡眠对血糖的影响

The Insidious Effects of Lost Sleep

Question:Does sleep play a role in glucose metabolism and the developmentof type 2 diabetes?

Answer:Before I answer this question directly, I think it is importantto note that Americans' sleep habits have changed significantlyover the last century. The National Sleep Foundation's annualsurveys of Americans' sleep habits indicate that Americans aresleeping less and less.¹Even though the average requirementfor sleep is likely 8–9 hours, many Americans average<7 hours, with some getting 5–6 hours most of the time.²Thus, sleep deprivation is endemic in our society.

With this as the backdrop, an increasing body of epidemiologicaland experimental data suggests that sleep deprivation hurtsour overall health and functioning, and specifically may affectthe development of diseases such as diabetes.

Epidemiological studies—largely conducted in men—haveshown fairly consistently that those who regularly sleep5 hours,or >8 hours, are at some increased risk for developing type2 diabetes.^3,4There is also evidence that individuals withtype 2 diabetes who report poor quality sleep or short sleepduration have increased glycated hemoglobin (A1C) levels.⁵

Experimental studies also support this phenomenon and revealsome possible mechanisms for the relationship. Sleep loss innormal volunteers appears to significantly affect the hypothalamicpituitary system, as well as the autonomic nervous system, bothof which in turn affect metabolism and, specifically, insulin resistance.⁶

Sleep curtailment alters the pattern of growth hormone secretion,reduces concentrations of thyroid stimulating hormone, and increasesevening cortisol levels, all of which can be mechanisms foran increase in insulin resistance. Other characteristics ofsleep deprivation are increased sympathetic activity and lessparasympathetic activity, which also affect glucose metabolismand the release of insulin.

Yet more experimental data shed light on sleep deprivation'simpact on hormones related to appetite and satiety. Sleep restrictionappears related to reductions in the appetite suppressant leptinand elevations in the appetite stimulant ghrelin. As a result,people low on sleep tend to experience increased hunger andappetite, especially for foods with high carbohydrate content.⁷Sleep loss, therefore, seems to alter the ability of leptinand ghrelin to accurately signal caloric need, and could leadto excessive caloric intake when food is freely available. Thus,sleep loss could drive individuals toward obesity, cardiometabolicrisk, and sleep apnea.

Lastly, an increasing body of data indicates that obstructivesleep apnea is an independent risk factor for type 2 diabetes.Further, it appears that apnea may also be modulated throughautonomic dysfunction and metabolic and endocrine changes thataffect insulin resistance.⁸

I strongly recommend that individuals diagnosed with type 2diabetes be screened for obstructive sleep apnea syndrome, especiallyif they are overweight. Similarly, physicians should be alertto the possibility of impaired glucose tolerance or insulinresistance in patients who have obstructive sleep apnea, particularlyif those patients are overweight.

Footnotes

Do you have a clinical question? Send it todocnews@diabetes.org.

Sam Fleishman, MD, is medicaldirector of the Sleep Center of Cape Fear Valley Health Systemin Fayetteville, N.C.

References

1.Kripke D, Simons R, Garfinkel L, et al.: Short and long sleep and sleeping pills: Is increased mortality associated?Arch Gen Psychiatr36:103–116, 1979.[Abstract]

2.National Sleep Foundation: 2002Sleep in America Poll. Washington, D.C., National Sleep Foundation. Available online atwww.sleepfoundation.org/site/c.huIXKjM0IxF/b.2417355/k.143E/2002_Sleep_in_America_Poll.htm. Accessed September 12, 2007.

3.Yaggi HK, Araujo AB, McKinlay JB: Sleep duration as a risk factor for the development of type 2 diabetes.Diabetes Care29: 657–661, 2006.[Abstract/Free Full Text]

4.Mallon L, Broman JE, Hetta J: High incidence of diabetes in men with sleep complaints or short sleep duration: A 12-year follow-up study of a middle-aged population.Diabetes Care28: 2762–2767, 2005.[Abstract/Free Full Text]

5.Knutson KL, Ryden AM, Mander BA, et al.: Role of sleep duration and quality in the risk and severity of type 2 diabetes mellitus.Arch Intern Med166:1768–1774, 2006.[Abstract/Free Full Text]

6.Van Cauter E, Knutson K, Leproult R, et al.: The impact of sleep deprivation on hormones and metabolism. Published online athttp://www.medscape.com/viewarticle/502825April 28, 2005. Accessed August 23, 2007.

7.Taheri S, Lin L, Austin D, et al.: Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index (BMI).Sleep27:A146–A147, 2004.

8.Chasens ER, Weaver TE, Umlauf MG: Insulin resistance and obstructive sleep apnea: Is increased sympathetic stimulation the link?Biol Res Nurs5:87–96, 2003.[Abstract/Free Full Text]