# A Scoping Review of Glucose Spikes in People Without Diabetes: Comparing Insights from Grey Literature and Medical Research

## TL;DR

This study compares medical and grey literature to assess if glucose spikes affect health in non-diabetic people, finding some alignment but also discrepancies.

## Contribution

The study is novel in comparing peer-reviewed and grey literature to evaluate the health impact of glucose spikes in non-diabetic individuals.

## Key findings

- Both medical and grey literature agree glucose spikes can cause endothelial dysfunction and inflammation.
- Grey literature links spikes to cancer and mental health effects, which are not confirmed in medical studies.
- Long-term frequent glucose spikes are more likely to cause significant health issues than isolated spikes.

## Abstract

The use of continuous glucose monitoring (CGM) has grown, extending its use to people without diabetes. CGM helps prevent hyperglycaemia-related complications in diabetes, however, its value in people without diabetes remains uncertain. Despite online sources framing glucose spikes as harmful, studies show that overall, most healthy individuals maintain normal glucose levels – therefore questioning the significance of these spikes. This project aims to examine whether glucose spikes affect the health of people without diabetes. By comparing the medical and grey literature, we aim to determine whether the grey literature aligns with the peer-reviewed medical literature, or whether it could cause harm through misinformation.

Population: people without diabetes and human endothelial cells; Concept: the effect of glucose spikes on health; Context: global studies and grey literature. Following the PRISMA-ScR guidelines, a systematic search was undertaken via Medline, Embase and Proquest. Fifty-nine sources were reviewed − 11 medical research papers and 48 grey literature sources. Excel spreadsheets were developed and piloted for the medical and grey literature respectively. Data was extracted and charted, and a narrative synthesis was formulated.

Both the medical and grey literature reported glucose spikes can cause endothelial dysfunction, oxidative stress and inflammation in people without diabetes or human endothelial cells. However, the grey literature reported additional effects that is, increased risk of cancer and effects on mental health, energy, mood and sleep.

Glucose spikes may impact the health of people without diabetes, but significant health outcomes likely stem from long-term frequent spikes rather than isolated acute spikes. Discrepancies between the medical and grey literature highlight potential for misinformation in the grey literature, although the author does not claim cited sources are misleading, nor does the absence of claims in medical literature mean grey literature is misinforming. Further research is needed to verify if grey literature claims align with peer-reviewed evidence, as hypothetically, misinformation could significantly impact consumer wellbeing.

Evaluation of the effects of sudden increases in blood sugar (glucose spikes) in people without diabetes

Introduction Public awareness of glucose spikes has increased, and there have been developments in use of continuous glucose monitoring (CGM) in people without diabetes to monitor glucose spikes. Whilst CGM helps prevent diabetes complications like stroke and nerve damage, it is unclear whether CGM and controlling glucose spikes affect overall health in people without diabetes. There is little research published about glucose spikes in healthy people, and it is important to understand if CGM can be beneficial or whether it can cause unhealthy eating habits. This paper compares current research with information published in newspapers, magazines and blogs (grey literature). Methods A scoping review method was chosen to compare medical evidence with grey literature, to identify gaps in the knowledge and to make recommendations for future practice. Medline and Embase databases were searched using key terms. Proquest database was searched for grey literature. The data was extracted from the reviewed papers using an excel data extraction spreadsheet, then reviewed and summarised. Results Both the medical and grey literature reported that glucose spikes can affect blood vessel function, increase cell damage and inflammation in people without diabetes or human cells. However, the grey literature also links spikes to risks like cancer, mental health issues, and impacts on energy, mood, and sleep. Conclusion Glucose spikes may affect the health of people without diabetes. However, significant health problems are more likely to be from repeated glucose spikes rather than one-off spikes. Differences between the medical and grey literature suggest potential for misinformation, though we do not suggest grey sources in this paper are misinforming. Further research is needed to understand whether the additional claims in the grey literature have equivalent medical evidence as hypothetically the effect of misinformation on the public could be considerable.