10-year study finds that the higher the blood sugar level, the faster the cognitive decline over time — regardless of diabetic status

by

___

The Star­tling Link Between Sug­ar and Alzheimer’s (The Atlantic):

“A lon­gi­tu­di­nal study, pub­lished Thurs­day in the jour­nal Dia­betolo­gia, fol­lowed 5,189 peo­ple over 10 years and found that peo­ple with high blood sug­ar had a faster rate of cog­ni­tive decline than those with nor­mal blood sugar—whether or not their blood-sug­ar lev­el tech­ni­cal­ly made them dia­bet­ic. In oth­er words, the high­er the blood sug­ar, the faster the cog­ni­tive decline.

“Demen­tia is one of the most preva­lent psy­chi­atric con­di­tions strong­ly asso­ci­at­ed with poor qual­i­ty of lat­er life,” said the lead author, Wux­i­ang Xie at Impe­r­i­al Col­lege Lon­don, via email. “Cur­rent­ly, demen­tia is not cur­able, which makes it very impor­tant to study risk fac­tors”… That’s an impor­tant point that often gets for­got­ten in dis­cus­sions of Alzheimer’s. It’s such a hor­ri­ble dis­ease that it can be tempt­ing to dis­miss it as inevitable. And, of course, there are genet­ic and oth­er, non-nutri­tion­al fac­tors that con­tribute to its pro­gres­sion. But, as these and oth­er researchers point out, deci­sions we make about food are one risk fac­tor we can con­trol. And it’s start­ing to look like deci­sions we make while we’re still rel­a­tive­ly young can affect our future cog­ni­tive health.”

The Study

HbA1c, dia­betes and cog­ni­tive decline: the Eng­lish Lon­gi­tu­di­nal Study of Age­ing (Dia­betolo­gia):

  • Aims/hypothesis: The aim of the study was to eval­u­ate lon­gi­tu­di­nal asso­ci­a­tions between HbA1c lev­els, dia­betes sta­tus and sub­se­quent cog­ni­tive decline over a 10 year fol­low-up period.
  • Meth­ods: Data from wave 2 (2004–2005) to wave 7 (2014–2015) of the Eng­lish Lon­gi­tu­di­nal Study of Age­ing (ELSA) were analysed. Cog­ni­tive func­tion was assessed at base­line (wave 2) and reassessed every 2 years at waves 3–7. Lin­ear mixed mod­els were used to eval­u­ate lon­gi­tu­di­nal associations.
  • Conclusions/interpretation: In con­clu­sion, our study pro­vides evi­dence to sup­port the asso­ci­a­tion of dia­betes with sub­se­quent cog­ni­tive decline. More­over, our find­ings show a lin­ear cor­re­la­tion between cir­cu­lat­ing HbA1c lev­els and cog­ni­tive decline, regard­less of dia­bet­ic sta­tus. Future stud­ies are required to deter­mine the long-term effects of main­tain­ing opti­mal glu­cose con­trol on cog­ni­tive decline in peo­ple with diabetes.

The Study In Context