Influence of hypoglycaemia, with or without caffeine ingestion, on visual sensation and performance

G Owen, J Watson, A McGown, S Sharma, I Deary, D Kerr, G Barrett

Research output: Contribution to journalArticlepeer-review


Full-field visual evoked potentials and visual information processing were measured in 16 normal, healthy subjects during a hyperinsulinaemic damp. A randomized cross-over design was used across three conditions: hypoglycaemia and caffeine; hypoglycaemia and placebo; and euglycaemia and caffeine. The latency of the P100 component of the pattern-reversal visual evoked potential increased significantly from rest to hypoglycaemia, but no effect of caffeine was found. Subjects were subsequently divided into two median groups based on the increase in P 100 latency in the placebo condition (Group 1, +0.5 ms; Group 2, +5.6 ms). In the absence of caffeine. an inverse correlation between the increase in P100 latency from rest and a deterioration in visual movement detection was found for Group 2, but not for Group I. Caffeine ingestion resulted in a further increase in P100 latency, from rest to hypoglycaemia. for subjects in Group 2. Hypoglycaemia in the absence of caffeine produces changes in visual sensation from rest to hypoglycaemia. In those subjects most sensitive to the effects of hypoglycaemia (Croup 2), the increase in P100 latency was associated with poorer performance in tests of visual information processing. Caffeine ingestion produced further increases in P100 latency in these subjects.

Original languageEnglish
Pages (from-to)619-626
Number of pages8
JournalClinical science
Issue number6
Publication statusPublished - Jun 2001


  • caffeine
  • hypoglycaemia
  • visual evoked potential
  • visual performance
  • visual sensation

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