Hypoglycaemia in diabetes

The Experience of Hypoglycaemia and Strategies Used For Its Management by Community-Dwelling Adults with Diabetes Mellitus: A Systematic Review

BACKGROUND

Hypoglycaemia, a common complication of diabetes drug therapy, has been reported to influence therapy adherence and the quality of life of people with diabetes mellitus. No systematic reviews on the experience of hypoglycaemia have been undertaken. The extant literature has taken a medical model perspective focusing on the causes, prevalence, and impact of hypoglycaemia. To understand the meaningfulness of hypoglycaemia and how this condition impacts on a person with diabetes mellitus, a systematic review was undertaken exploring the experiences of hypoglycaemia in community-dwelling people with diabetes mellitus.

OBJECTIVE

This review aimed to synthesise evidence on the experience of hypoglycaemia, and the strategies used to control it in community-dwelling adults with type 1 and type 2 diabetes mellitus.

INCLUSION CRITERIA

Type of Participants - Community-dwelling adults (18 years of age and over) who had experienced hypoglycaemia from type 1 or type 2 diabetes mellitus and/or who had used self-management strategies for hypoglycaemia were included.Phenomena of Interest - The experiences of hypoglycaemia in community-dwelling adults with diabetes mellitus and the strategies they used to self-manage hypoglycaemia were included.Type of Studies - Qualitative studies including, but not limited to, designs such as phenomenology, grounded theory, ethnography, action research and feminist research were included.

SEARCH STRATEGY

Published and unpublished studies in English from January 2000 to August 2010 were gathered using a three-step search strategy. An initial limited search was conducted in MEDLINE and CINAHL to identify keywords and index terms, which were then used in a second search across the CINAHL, PUBMED, SCOPUS, PsycINFO, PsycARTICLES, Web of Science, JSTOR, EMBASE and MEDNAR databases. Additionally, the reference list of all studies was hand-searched for additional studies.

METHODOLOGICAL QUALITY

Two reviewers independently assessed the retrieved studies for methodological validity, using standardised Joanna Briggs Institute-Qualitative Assessment and Review Instrument (JBI-QARI) critical appraisal instruments. Disagreements that arose between the two reviewers were resolved with the help of a third reviewer.

DATA COLLECTION

Data, in terms of research findings, were extracted from included studies using the standardised JBI-QARI data extraction tool.

DATA SYNTHESIS

These findings were then pooled and assembled into level 1 findings, then level 2 findings (categories), and lastly meta-synthesised to form one level 3 synthesised finding. Meta-aggregation was carried out using JBI-QARI.

RESULTS

Six studies were included in the review. Participants who lived independently in the community and attended primary care or outpatient clinics were included. In total, twenty findings were grouped into three categories, which were synthesised into one overall finding - i.e., "People with diabetes mellitus can self-manage their diabetes and thus prevent hypoglycaemic episodes more effectively when health professionals provide psychological, physiological and spiritual support, and an individually targeted education programme".

CONCLUSIONS

The review findings revealed patient-identified priorities to maintain normality in blood glucose self-management. There is also evidence that some people lack the knowledge to identify and self-manage hypoglycaemia.To enable community-dwelling adults with diabetes mellitus to self-manage hypoglycaemia, healthcare professionals should provide individualised information and emotional support, and regularly discuss and assess the person's level of knowledge, awareness of hypoglycaemia, and their ability to self-manage.There is a lack of data that capture the person's experience and awareness of hypoglycaemia and how they self-manage the condition, particularly in varying cultural contexts. A mixed-method study could be designed to explore the experiences of hypoglycaemia, and to develop and validate a reliable tool that assesses the level of knowledge and awareness of hypoglycaemia, and the ability to self-manage. This study should include people with diabetes mellitus from different cultures and/or geographical locations.

Pharmacological properties and functional role of Kslow current in mouse pancreatic beta-cells: SK channels contribute to Kslow tail current and modulate insulin secretion

The pharmacological properties of slow Ca²⁺-activated K⁺ current (K_slow) were investigated in mouse pancreatic β-cells and islets to understand how K_slow contributes to the control of islet bursting, [Ca²⁺]_i oscillations, and insulin secretion. K_slow was insensitive to apamin or the K_ATP channel inhibitor tolbutamide, but UCL 1684, a potent and selective nonpeptide SK channel blocker reduced the amplitude of K_slow tail current in voltage-clamped mouse β-cells. K_slow was also selectively and reversibly inhibited by the class III antiarrythmic agent azimilide (AZ). In isolated β-cells or islets, pharmacologic inhibition of K_slow by UCL 1684 or AZ depolarized β-cell silent phase potential, increased action potential firing, raised [Ca²⁺]_i, and enhanced glucose-dependent insulin secretion. AZ inhibition of K_slow also supported mediation by SK, rather than cardiac-like slow delayed rectifier channels since bath application of AZ to HEK 293 cells expressing SK3 cDNA reduced SK current. Further, AZ-sensitive K_slow current was extant in β-cells from KCNQ1 or KCNE1 null mice lacking cardiac slow delayed rectifier currents. These results strongly support a functional role for SK channel-mediated K_slow current in β-cells, and suggest that drugs that target SK channels may represent a new approach for increasing glucose-dependent insulin secretion. The apamin insensitivity of β-cell SK current suggests that β-cells express a unique SK splice variant or a novel heteromultimer consisting of different SK subunits.