Well-being, cerebral function, and physical fatigue after nocturnal hypoglycemia in IDDM

Nocturnal hypoglycemia is associated with next day cognitive performance in adults with type 1 diabetes: Pilot data from the GluCog study

OBJECTIVE

 Individuals with type 1 diabetes (T1D) have increased risk for cognitive dysfunction and high rates of sleep disturbance. Despite associations between glycemia and cognitive performance using cross-sectional and experimental methods few studies have evaluated this relationship in a naturalistic setting, or the impact of nocturnal versus daytime hypoglycemia. Ecological Momentary Assessment (EMA) may provide insight into the dynamic associations between cognition, affective, and physiological states. The current study couples EMA data with continuous glucose monitoring (CGM) to examine the within-person impact of nocturnal glycemia on next day cognitive performance in adults with T1D. Due to high rates of sleep disturbance and emotional distress in people with T1D, the potential impacts of sleep characteristics and negative affect were also evaluated.

METHODS

 This pilot study utilized EMA in 18 adults with T1D to examine the impact of glycemic excursions, measured using CGM, on cognitive performance, measured via mobile cognitive assessment using the TestMyBrain platform. Multilevel modeling was used to test the within-person effects of nocturnal hypoglycemia and hyperglycemia on next day cognition.

RESULTS

 Results indicated that increases in nocturnal hypoglycemia were associated with slower next day processing speed. This association was not significantly attenuated by negative affect, sleepiness, or sleep quality.

CONCLUSIONS

 These results, while preliminary due to small sample size, showcase the power of intensive longitudinal designs using ambulatory cognitive assessment to uncover novel determinants of cognitive fluctuation in real world settings, an approach that may be utilized in other populations. Findings suggest reducing nocturnal hypoglycemia may improve cognition in adults with T1D.

Relationship between CGM-derived nocturnal hypoglycemia and subjective sleep quality in people with type 1 diabetes

This pilot study explores the relationship between nocturnal hypoglycemia (NH) and subjective sleep quality in people with type 1 diabetes (T1D). Twenty-seven adults with T1D wore a Freestyle Libre Pro CGM and recorded subjective sleep quality daily, as assessed by a single Likert scale question. Frequency, duration, area under the curve (AUC) of NH (00:00-06:00) defined as sensor glucose below threshold (< 3.9 mmol/L; < 3 mmol/L) for ≥ 15 min, nocturnal mean glucose, Time in Range (3.9-10 mmol/L), and coefficient of variation were calculated. Twenty-seven adults, 18 (66.7%) women, with median (IQR) age of 27 (26, 32) years and HbA1c of 7.6 (7.1, 8.1) participated. Nights with NH < 3.9 mmol/L resulted in a lower (worse) sleep score than nights without NH [Mean (SD): 3.3 (1.2) vs 3.5 (1.0), p = 0.03). A higher frequency and longer duration but not AUC [adjusted OR (95% CI) 0.52 (0.38, 0.72), 0.961 (0.932, 0.991), 0.999 (0.998, 1.001) respectively)], of NH < 3.9 mmol/L, were associated with a lower sleep score. NH < 3.0 mmol/L metrics were not associated with sleep quality. Recurrent NH < 3.9 mmol/L, rather than prolonged NH < 3.0 mmol/L, seems associated with subjective sleep quality, implying that those with the highest burden of NH are likely unaware of it.

Nocturnal hypoglycemia is underdiagnosed in older people with insulin-treated type 2 diabetes: The HYPOAGE observational study

BACKGROUND

There is a lack of real-life data regarding the frequency and predictive factors of hypoglycemia in older patients with type 2 diabetes (T2D). This study aimed to determine the frequency and predictors of hypoglycemia in older patients with insulin-treated T2D.

METHODS

This prospective multicenter study included 155 insulin-treated T2D patients aged 75 years and older with ≥2 self-monitoring of blood glucose (SMBG) daily controls. Participants underwent a geriatric and diabetic assessment and received ambulatory blinded continuous glucose monitoring (CGM) for 28 consecutive days with FreeStyle Libre Pro® sensor. Study population (n = 141) has >70% CGM active time. Multivariable logistic regressions were used to identify factors associated with SMBG confirmed hypoglycemia (≥70 mg/dL) and with nocturnal level 2 time below range (glucose concentration <54 mg/dL during ≥15 consecutive min between 0.00 and 6.00 am).

RESULTS

The mean age of the 141 analyzed patients was 81.5 ± 5.3 years and 56.7% were male. The mean baseline HbA_1c was 7.9% ± 1.0%. After geriatric assessment, 102 participants (72.3%) were considered as complex and 39 (27.7%) as healthy. The primary endpoint (confirmed SMBG <70 mg/dL) occurred in 37.6% patients. In multivariable analysis, the risk of SMBG-confirmed hypoglycemia was positively associated with a longer duration of diabetes (OR (+1 year) =1.04, (1.00-1.08), p = 0.04) and glycemic variability assessed by CGM (CV %) (OR (+1%) = 1.12, [1.05-1.19], p = <0.001). Nighty-two patients (65.2%) experienced nocturnal time in hypoglycemia (i.e., <54 mg/dL during ≥15 consecutive min between midnight and 6 a.m.). In multivariable analyses, cognitive impairment (OR: 9.31 [2.59-33.4]), heart failure (OR: 4.81 [1;48-15.6]), and depressive disorder (OR: 0.19 [0.06-0.53]) were associated with nocturnal time in hypoglycemia.

CONCLUSION

Nocturnal hypoglycemia is very common and largely underdiagnosed in older patients with insulin-treated T2D. CGM is a promising tool to better identify hypoglycemia and adapt diabetes management in this population.

Effects of Dietary Carbohydrate Profile on Nocturnal Metabolism, Sleep, and Wellbeing: A Review

Sleep is a crucial biological function and a well-established driver of health and wellbeing across the lifespan. In this review, we describe how sleep in humans is associated with specific circadian metabolic and physiological changes, and how the organization of sleep-wake states is related to regulation of nocturnal metabolism during fasting. Among the modifiable factors that can contribute to sleep-related benefits, emerging evidence suggests that diet and nocturnal changes in glucose regulation are strong determinants of sleep quality. Here, we review studies that have explored the importance of quantity and quality of dietary carbohydrates and proteins in modulation of sleep and sleep-related health benefits. Future research may guide the creation of nutritional solutions to improve sleep, which could lead to positive changes in health, wellbeing, and overall quality of life.

Changes in quality of life following hypoglycaemia in adults with type 2 diabetes: A systematic review of longitudinal studies

AIM

To conduct a systematic review of published studies reporting on the longitudinal impacts of hypoglycaemia on quality of life (QoL) in adults with type 2 diabetes.

METHOD

Database searches with no restrictions by language or date were conducted in MEDLINE, Cochrane Library, CINAHL and PsycINFO. Studies were included for review if they used a longitudinal design (e.g. cohort studies, randomised controlled trials) and reported on the association between hypoglycaemia and changes over time in patient-reported outcomes related to QoL.

RESULTS

In all, 20 longitudinal studies published between 1998 and 2020, representing 50,429 adults with type 2 diabetes, were selected for review. A descriptive synthesis following Synthesis Without Meta-analysis guidelines indicated that self-treated symptomatic hypoglycaemia was followed by impairments in daily functioning along with elevated symptoms of generalised anxiety, diabetes distress and fear of hypoglycaemia. Severe hypoglycaemic events were associated with reduced confidence in diabetes self-management and lower ratings of perceived health over time. Frequent hypoglycaemia was followed by reduced energy levels and diminished emotional well-being. There was insufficient evidence, however, to conclude that hypoglycaemia impacted sleep quality, depressive symptoms, general mood, social support or overall diabetes-specific QoL.

CONCLUSIONS

Longitudinal evidence in this review suggests hypoglycaemia is a common occurrence among adults with type 2 diabetes that impacts key facets in the physical and psychological domains of QoL. Nonetheless, additional longitudinal research is needed-in particular, studies targeting diverse forms of hypoglycaemia, more varied facets of QoL and outcomes assessed using hypoglycaemia-specific measures.

Type 1 Diabetes, Sleep, and Hypoglycemia

PURPOSE OF REVIEW

To review the relationship between sleep and hypoglycemia, sleep characteristics, and their associations with glycemic control in persons with type 1 diabetes (T1D). The effects of sleep interventions and diabetes technology on sleep are summarized.

RECENT FINDINGS

Nocturnal hypoglycemia affects objective and subjective sleep quality and is related to behavioral, psychological, and physiological factors. Sleep disturbances are common, including inadequate sleep, impaired sleep efficiency, poor subjective satisfaction, irregular timing, increased daytime sleepiness, and sleep apnea. Some have a bidirectional relationship with glycemic control. Preliminary evidence supports sleep interventions (e.g., sleep extension and sleep coach) in improving sleep and glycemic control, while diabetes technology use could potentially improve sleep. Hypoglycemia and sleep disturbances are common among persons with T1D. There is a need to develop sleep promotion programs and test their effects on sleep, glucose, and related outcomes (e.g., self-care, psychological health).

Contributing factors of fatigue in patients with type 2 diabetes: A systematic review

Remarkable evidence supports the link between type 2 diabetes (T2DM) and fatigue. However, a unifying recommendation to identify and prevent fatigue or to prevent its clinical consequences in T2DM is not available at present. Therefore, this study aimed to conduct a systematic review to summarize the definition, measurement tools, and contributing factors of fatigue in T2DM. Nine articles were included for analysis, and results showed that T2DM fatigue was associated with five major factors, including sociodemographic factors, clinical disease factors, inflammatory factors, psychological factors, and behavior and lifestyle. The contributing factors of T2DM fatigue are reviewed, and clinical benefits provide a theoretical basis for further clinical intervention to prevent the occurrence of fatigue and improve the patient's treatment compliance and self-management ability and may be beneficial to their quality of life.

Glucose Regulation Beyond HbA1c in Type 2 Diabetes Treated With Insulin: Real-World Evidence From the DIALECT-2 Cohort

OBJECTIVE

To investigate glucose variations associated with glycated hemoglobin (HbA1c) in insulin-treated patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients included in Diabetes and Lifestyle Cohort Twente (DIALECT)-2 (n = 79) were grouped into three HbA1c categories: low, intermediate, and high (≤53, 54-62, and ≥63 mmol/mol or ≤7, 7.1-7.8, and ≥7.9%, respectively). Blood glucose time in range (TIR), time below range (TBR), time above range (TAR), glucose variability parameters, day and night duration, and frequency of TBR and TAR episodes were determined by continuous glucose monitoring (CGM) using the FreeStyle Libre sensor and compared between HbA1c categories.

RESULTS

CGM was performed for a median (interquartile range) of 10 (7-12) days/patient. TIR was not different for low and intermediate HbA1c categories (76.8% [68.3-88.2] vs. 76.0% [72.5.0-80.1]), whereas in the low category, TBR was higher and TAR lower (7.7% [2.4-19.1] vs. 0.7% [0.3-6.1] and 8.2% [5.7-17.6] vs. 20.4% [11.6-27.0], respectively, P < 0.05). Patients in the highest HbA1c category had lower TIR (52.7% [40.9-67.3]) and higher TAR (44.1% [27.8-57.0]) than the other HbA1c categories (P < 0.05), but did not have less TBR during the night. All patients had more (0.06 ± 0.06/h vs. 0.03 ± 0.03/h; P = 0.002) and longer (88.0 [45.0-195.5] vs. 53.4 [34.4-82.8] minutes; P < 0.001) TBR episodes during the night than during the day.

CONCLUSIONS

In this study, a high HbA1c did not reduce the occurrence of nocturnal hypoglycemia, and low HbA1c was not associated with the highest TIR. Optimal personalization of glycemic control requires the use of newer tools, including CGM-derived parameters.

Effects of continuous glucose monitor-recorded nocturnal hypoglycaemia on quality of life and mood during daily life in type 1 diabetes

AIMS/HYPOTHESIS

The aim of this work was to assess the effect of spontaneous nocturnal hypoglycaemia on quality of life and mood during subsequent days in type 1 diabetes.

METHODS

A total of 153 people with type 1 diabetes participated in 6 days of blinded continuous glucose monitoring while documenting hypoglycaemic symptoms, quality of life and mood, daily. Hypoglycaemia was defined by interstitial glucose ≤3.9 mmol/l (IG_3.9) and ≤ 3.0 mmol/l (IG_3.0) for ≥15 min and was classified as asymptomatic if no hypoglycaemic symptoms were reported.

RESULTS

Self-estimated quality of life assessed by the EQ-5D VAS (but not by the WHO Well-Being Index) was higher the day after asymptomatic (but not after symptomatic) hypoglycaemic nights, as compared with non-hypoglycaemic nights (IG_3.9, p = 0.021; IG_3.0, p = 0.048). The effect increased with lower glucose nadir and longer duration of nocturnal hypoglycaemia (IG_3.9, p = 0.03). The finding was confined to participants with impaired hypoglycaemia awareness. There was no effect of nocturnal hypoglycaemia on mood or self-estimated effectiveness at work the following day.

CONCLUSIONS/INTERPRETATION

Individuals with type 1 diabetes and impaired hypoglycaemia awareness reported higher quality of life on days preceded by nights with asymptomatic (but not symptomatic) hypoglycaemia. The effect was amplified by lower glucose nadir and longer duration of the episodes and may help explain resistance to implementation of interventions to reduce hypoglycaemia in many people with impaired hypoglycaemia awareness.

A systematic review of the effect of prior hypoglycaemia on cognitive function in type 1 diabetes

BACKGROUND

The effect of prior hypoglycaemia on cognitive function in type 1 diabetes is an important unresolved clinical question. In this systematic review, we aimed to summarize the studies exploring the impact of prior hypoglycaemia on any aspect of cognitive function in type 1 diabetes.

METHODS

We used a multidatabase search platform Healthcare Database Advanced Search to search Medline, PubMed, EMBASE, EMCARE, CINAHL, PsycINFO, BNI, HMIC, and AMED from inception until 1 May 2019. We included studies on type 1 diabetes of any age. The outcome measure was any aspect of cognitive function.

RESULTS

The 62 studies identified were grouped as severe hypoglycaemia (SH) in childhood (⩽18 years) and adult-onset (>18 years) diabetes, nonsevere hypoglycaemia (NSH) and nocturnal hypoglycaemia (NH). SH in early childhood-onset diabetes, especially seizures and coma, was associated with poorer memory (verbal and visuospatial), as well as verbal intelligence. Among adult-onset diabetes, SH was associated with poorer cognitive performance in the older age (>55 years) group only. Early versus late exposure to SH had a significant association with cognitive dysfunction (CD). NSH and NH did not have any significant association with CD, while impaired awareness of hypoglycaemia was associated with poorer memory and cognitive-processing speeds.

CONCLUSION

The effect of SH on cognitive function is age dependent. Exposure to SH in early childhood (<10 years) and older age groups (>55 years) was associated with a moderate effect on the decrease in cognitive function in type 1 diabetes [PROSPERO ID: CRD42019141321].

The Association of Biochemical Hypoglycemia with the Subsequent Risk of a Severe Hypoglycemic Event: Analysis of the DCCT Data Set

OBJECTIVE

To evaluate the association of biochemical hypoglycemia with subsequent severe hypoglycemia (SH) events using the Diabetes Control and Complications Trial (DCCT) data set.

RESEARCH DESIGN AND METHODS

The frequency of biochemical hypoglycemia (percentage of values <70 and <54 mg/dL [3.9 and 3.0 mmol/L) was assessed using DCCT blood glucose concentrations measured at a central laboratory from seven finger-stick samples (7-point testing: pre- and 90-min postmeals and at bedtime) collected during 1 day every 3 months. SH events required a change in mental status necessitating the involvement of another individual to provide treatment. A Poisson model accounting for repeated measures from each participant was used to assess the association of biochemical hypoglycemia frequency, computed from the 7-point finger-stick data, with the development of SH events.

RESULTS

The risk of SH during a 3-month period was substantially higher (P < 0.001) when there was at least one hypoglycemic blood glucose value in the preceding 7-point profile, with similar results seen for both the 70 mg/dL (rate ratio = 3.0 [95% confidence interval: 2.6-3.3]) and 54 mg/dL (rate ratio = 2.7 [95% confidence interval: 2.4-3.1]) thresholds.

CONCLUSIONS

The occurrence of biochemical hypoglycemia <70 or <54 mg/dL is associated with an increased risk of SH. For this reason as well as the deleterious effects of hypoglycemia on glucose counter-regulation and hypoglycemia awareness, cognition, quality of life, and arrhythmias, it is important in diabetes management to avoid hypoglycemic glucose levels as much as possible.

Usage of continuous glucose monitoring (CGM) for detecting an unrecognized hypoglycemia and management of glucocorticoid replacement therapy in adult patients with central hypoadrenalism

Patients with adrenal insufficiency require appropriate glucocorticoid replacement therapy; however, reliable biological parameters for optimizing glucocorticoid supplementation are limited. The physician has to rely primarily on clinical judgment, carefully taking into account signs and symptoms potentially suggestive of over- or under-replacement. We have found that some patients who are viewed as receiving sufficient doses of glucocorticoids occasionally exhibit morning headache or morning discomfort, which may be caused by unrecognized nocturnal hypoglycemia. Our aim in this study was to evaluate the usefulness of continuous glucose monitoring (CGM) for detecting unrecognized hypoglycemia and optimizing glucocorticoid replacement therapy in adult patients with central hypoadrenalism. Six patients with central hypoadrenalism of various etiologies were included in this study. All patients exhibited occasional morning headache or discomfort. We performed CGM to measure plasma glucose levels in all patients, and CGM identified unrecognized hypoglycemia episodes at midnight and early in the morning in five patients (83%). The CGM findings were used to fine-tune the dosing and regimens of glucocorticoid replacement and to re-evaluate glucose levels to avoid further unrecognized hypoglycemic events. This optimization of hydrocortisone supplementation prevented additional nocturnal hypoglycemia incidences in all cases. The addition of L-thyroxine with hydrocortisone continued to provide favorable glycemic control. Occasional symptoms also improved after maintenance in all patients. These findings demonstrated that CGM may represent a powerful tool for identifying unrecognized hypoglycemia and for optimizing supplementary hormones in patients with central hypoadrenalism, thereby improving their quality of life.

Fear of hypoglycemia in patients with type 2 diabetes: The role of interoceptive accuracy and prior episodes of hypoglycemia

OBJECTIVE

Fear of hypoglycemia (FoH) is a limiting factor for diabetes self-management and can have detrimental effects on quality of life. However, relatively little is known about its underlying mechanisms. In line with findings on patients with anxiety disorders, we hypothesized that interoceptive accuracy (IA) might be positively linked to FoH in patients with type 2 diabetes (T2DM).

METHODS

133 patients with T2DM were screened according to the extreme quartiles of the Hypoglycemia Fear Survey worry subscale (HFS-W). Overall, 66 participants (HFS-W<4; HFS-W>17) were included in the present study. Participants completed questionnaires on sociodemographic and diabetes-related measures. Accuracy of heartbeat perception was assessed using the mental tracking task.

RESULTS

Contrary to expectations, IA did not differ significantly between patients with low and high FoH. A linear regression analysis demonstrated that the experience of mild hypoglycemia (β=0.32, p≤0.01) and its interaction with IA (β=-0.26, p=0.040) were significant predictors of FoH, indicating that low IA and a history of experiencing mild hypoglycemia are positively associated with FoH.

CONCLUSION

Our findings suggest a positive association of low IA in combination with prior episodes of hypoglycemia and FoH in patients with T2DM. The results are in line with recent findings on IA in patients with chronic somatic symptom distress more generally and contribute to our understanding of the relations between interoception, body related fears, and physical symptom perception.

Estimating the risk of severe hypoglycemic event related to glucose-lowering treatment among Italian patients with diabetes: the HYPOTHESIS database

The primary objective of this study was to estimate 1) the annual risk of undergoing a severe hypoglycemic event in Italian patients with diabetes and 2) the risk of hospitalization following such event. From the HYPOTHESIS database, powered by 46 emergency departments covering a 12-million-odd population, data were extracted of 1,922 hypoglycemic events occurring in patients with diabetes in 2011. The mean age was 71.5 (standard deviation 16.8) years, 50.1% were men, and blood glucose at the time of the event was 44.2 (26.5) mg/dL. Patients were being treated with insulin alone (55%) or in combination with oral hypoglycemic agents (OHA, 15%), or with OHA alone, either in monotherapy (14%) or in multiple therapy (16%). Comorbidities were recorded in 71.8% of the patients. Based on the rates of glucose-lowering drug use in Italian patients with diabetes, the annual risk of undergoing a serious hypoglycemic event was estimated at 1.27% for subjects treated with insulin alone, the highest (p<0.00001) as compared with insulin + OHA (0.41%) or OHA alone, either in monotherapy or in multiple therapy (0.1% and 0.17%, respectively). The risk of being hospitalized following the hypoglycemic event was the least (27.6%) for subjects treated with insulin alone (p<0.0083). Subjects treated with insulin + OHA showed a lower risk (34.2%) as compared with that for subjects treated with OHA (p<0.02). Death occurs in 7% of hospitalized patients. Older age (p<0.0001) and comorbidities (p<0.0001) were risk factors for hypoglycemia-related hospitalization. Treatments with insulin alone (p<0.005) or in combination (p<0.049) were negatively associated with hospital admission. Severe hypoglycemic events associated with the use of oral glucose-lowering agents carry the highest risk of hospital treatment. As such, they are also likely to generate higher tangible and intangible costs.

Focus group study to identify the central facets of fear of hypoglycaemia in people with Type 2 diabetes mellitus

AIMS

To determine key worries about hypoglycaemia among insulin-using adults with Type 2 diabetes using a focus group approach.

METHODS

Thirteen focus groups were conducted in three diabetes outpatient care units and one peer support group was set up, in Germany. A total of 64 insulin-dependent adults with Type 2 diabetes (36.5% women, mean age 65.2 ± 11.0 years) discussed their worries about hypoglycaemia. The qualitative results were assigned into thematic categories using a bottom-up coding procedure. Participants completed the Hypoglycaemia Fear Survey and demographic measures were recorded. The results of the Hypoglycaemia Fear Survey were contrasted with the focus group findings to evaluate how accurately the Hypoglycaemia Fear Survey comprehensively captures features of fear of hypoglycaemia in Type 2 diabetes.

RESULTS

Eight themes were identified: 'unconsciousness/death'; 'aloneness/ helplessness', 'fear of hurting somebody'; 'shame'; 'loss of physical control'; 'long-term complications'; 'diabetes self-management issues'; and 'impaired awareness'. A total of 30 participants (46.9%) scored ≥3 on at least one item of the Hypoglycaemia Fear Survey worry subscale, indicating elevated worries. The Hypoglycaemia Fear Survey comprehensively captured all identified themes. Self-efficacy with regard to diabetes self-management seemed to play an important role in fear of hypoglycaemia in Type 2 diabetes.

CONCLUSIONS

Given that even subclinical worries can have negative effects on quality of life and diabetes self-management, emphasis should be placed on diabetes education; in particular, to help patients to develop self-efficacy concerning diabetes self-management. The Hypoglycaemia Fear Survey comprehensively captures hypoglycaemia worries in Type 2 diabetes. Additional assessment of self-efficacy might be beneficial to identify people at risk of developing hypoglycaemia worries.

The risks of nocturnal hypoglycaemia in insulin-treated diabetes

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia.

The effect of adding metformin to insulin therapy for type 1 diabetes mellitus children: A systematic review and meta-analysis

We aimed to assess the effectiveness of adding metformin to insulin in type 1 diabetes mellitus (T1DM) children for improving metabolic outcomes. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) conducted on children age 6 to 19 years who are diagnosed with T1DM, and examined the effect of adding Metformin to standard insulin therapy. We performed literature searches on Ovid Midline, Ovid Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) from the date of inception of the database to February 15, 2016. Two reviewers screened titles and abstracts independently, assessed full text eligibility, and extracted information from eligible trials. The primary outcome is glycated hemoglobin (HbA1c), and the secondary outcomes are health-related quality of life, body mass index (BMI), lipid profile, total insulin daily dose, hypoglycaemia, and diabetes ketoacidosis. We screened 736 studies, and included 6 RCTs with 325 patients. All RCTs were of low risk of bias, and included adolescents (mean age 15 years). The meta-analysis showed that the addition of Metformin resulted in decreased total insulin daily dose (TIDD) (unit/kg/d) (mean difference [MD] = -0.15, 95%CI, -0.24, -0.06), and reduced BMI kg/m² (MD -1.46, 95%CI -2.54, 0.38), and BMI z-score (MD= - 0.11, 95%CI -0.21, -0.01), and similar HbA1c (%) (MD= - 0.05, 95%CI, -0.19, 0.29). The overall evidence quality was high to moderate. Current evidence does not support use of Metformin in T1DM adolescents to improve HbA1c. However, Metformin may provide modest reduction in TIDD and BMI.

Self-reported Hypoglycaemia in Patients treated with Insulin: A Large Slovenian Retrospectively-prospective Study

INTRODUCTION

Hypoglycaemia is the major barrier for glycaemic target achievement in patients treated with insulin. The aim of the present study was to investigate real-world incidence and predictors of hypoglycaemia in insulin-treated patients.

METHODS

More than 300 consecutive patients with type 1 or type 2 diabetes treated with insulin were enrolled during regular out-patient visits from 36 diabetes practices throughout the whole country. They completed a comprehensive questionnaire on hypoglycaemia knowledge, awareness, and incidence in the last month and last six months. In addition, in the prospective part, patients recorded incidence of hypoglycaemic events using a special diary prospectively on a daily basis, through 4 weeks.

RESULTS

At least one hypoglycaemic event was self-reported in 84.1%, and 56.4% of patients with type 1 and type 2 diabetes, respectively, during the prospective period of 4 weeks. 43.4% and 26.2% of patients with type 1 and type 2 diabetes, respectively, experienced a nocturnal hypoglycaemic event. In the same time-period, severe hypoglycaemia was experienced by 15.9% and 7.1% of patients with type 1 and type 2 diabetes, respectively. Lower glycated haemoglobin was not a significant predictor of hypoglycaemia.

CONCLUSIONS

Rates of self-reported hypoglycaemia in patients treated with insulin in the largest and most comprehensive study in Slovenia so far are higher than reported from randomised control trials, but comparable to data from observational studies. Hypoglycaemia incidence was high even with high glycated haemoglobin values.

Comparing effects of insulin analogues and human insulin on nocturnal glycaemia in hypoglycaemia-prone people with Type 1 diabetes

AIMS

To assess the difference between analogue and human insulin with regard to nocturnal glucose profiles and risk of hypoglycaemia in people with recurrent severe hypoglycaemia.

METHODS

A total of 72 people [46 men, mean ± sd age 54 ± 12 years, mean ± sd HbA_1c 65 ± 12 mmol/mol (8.1 ± 1.1%), mean ± sd duration of diabetes 30 ± 14 years], who participated in a 2-year randomized, crossover trial of basal-bolus therapy with insulin detemir/insulin aspart or human NPH insulin/human regular insulin (the HypoAna trial) were studied for 2 nights during each treatment. Venous blood was drawn hourly during sleep. Primary endpoints were nocturnal glucose profiles and occurrence of hypoglycaemia (blood glucose ≤ 3.9 mmol/l).

RESULTS

During insulin analogue treatment, the mean nocturnal plasma glucose level was significantly higher than during treatment with human insulin (10.6 vs 8.1 mmol/l). The fasting plasma glucose level was similar between the treatments. Nocturnal hypoglycaemia was registered during 41/101 nights (41%) in the human insulin arm and 19/117 nights (16%) in the insulin analogue arm, corresponding to a hazard ratio of 0.26 (95% CI 0.14 to 0.45; P < 0.0001) with insulin analogue.

CONCLUSIONS

Treatment with insulin analogue reduces the occurrence of nocturnal hypoglycaemia assessed by nocturnal glucose profiles in people with Type 1 diabetes prone to severe hypoglycaemia. Nocturnal glucose profiles provide a more comprehensive assessment of clinical benefit of insulin regimens as compared to conventional recording of hypoglycaemia.

Reduced nocturnal hypoglycaemia with basal insulin peglispro compared with insulin glargine: pooled analyses of five randomized controlled trials

Basal insulin peglispro (BIL) is a novel basal insulin with hepato-preferential action, resulting from reduced peripheral effects. This report summarizes hypoglycaemia data from five BIL phase III studies with insulin glargine as the comparator, including three double-blind trials. Prespecified pooled analyses (n = 4927) included: patients with type 2 diabetes (T2D) receiving basal insulin only, those with T2D on basal-bolus therapy, and those with type 1 diabetes (T1D). BIL treatment resulted in a 36-45% lower nocturnal hypoglycaemia rate compared with glargine, despite greater reduction in glycated haemoglobin (HbA1c) and higher basal insulin dosing. The total hypoglycaemia rate was similar in patients with T2D on basal treatment only, trended towards being higher (10%) in patients with T2D on basal-bolus treatment (p = .053), and was 15% higher (p < .001) with BIL versus glargine in patients with T1D, with more daytime hypoglycaemia in the T1D and T2D groups who were receiving basal-bolus therapy. In T1D, during the maintenance treatment period (26-52 weeks), the total hypoglycaemia rate was not significantly different. There were no differences in severe hypoglycaemia in the T1D or T2D pooled analyses. BIL versus glargine treatment resulted in greater HbA1c reduction with less nocturnal hypoglycaemia in all patient populations, higher daytime hypoglycaemia with basal-bolus therapy in the T1D and T2D groups, and an associated increase in total hypoglycaemia in the patients with T1D.

Mechanisms of hypoglycemia unawareness and implications in diabetic patients

Hypoglycemia unawareness (HU) is defined at the onset of neuroglycopenia before the appearance of autonomic warning symptoms. It is a major limitation to achieving tight diabetes and reduced quality of life. HU occurs in approximately 40% of people with type 1 diabetes mellitus (T1DM) and with less frequency in T2DM. Though the aetiology of HU is multifactorial, possible mechanisms include chronic exposure to low blood glucose, antecedent hypoglycaemia, recurrent severe hypoglycaemia and the failure of counter-regulatory hormones. Clinically it manifests as the inability to recognise impeding hypoglycaemia by symptoms, but the mechanisms and mediators remain largely unknown. Prevention and management of HU is complex, and can only be achieved by a multifactorial intervention of clinical care and structured patient education by the diabetes team. Less know regarding the impact of medications on the development or recognition of this condition in patients with diabetes. Several medications are thought to worsen or promote HU, whereas others may have an attenuating effect on the problem. This article reviews recent advances in how the brain senses and responds to hypoglycaemia, novel mechanisms by which people with insulin-treated diabetes develop HU and impaired counter-regulatory responses. The consequences that HU has on the person with diabetes and their family are also described. Finally, it examines the evidence for prevention and treatment of HU, and summarizes the effects of medications that may influence it.

Assessing the impact of non-severe hypoglycemic events and treatment in adults: development of the Treatment-Related Impact Measure-Non-severe Hypoglycemic Events (TRIM-HYPO)

PURPOSE

Non-severe hypoglycemic events (NSHEs) are commonly experienced by diabetes patients, particularly among insulin users, and can have serious impacts on daily functioning, emotional well-being, sleep, work productivity, and treatment adherence. Currently, no PRO measures are available to assess the impacts of non-severe hypoglycemia. To address this gap, the Treatment-Related Impact Measure-Non-severe Hypoglycemic Events (TRIM-HYPO) was developed. This paper describes the TRIM-HYPO development and validation.

METHODS

The creation of the TRIM-HYPO followed FDA's guideline for PRO development. Concept elicitation data were gathered from literature review, clinical expert interviews, and focus groups of patients with Type 1 or 2 diabetes in four countries. Based on the qualitative analysis, draft items were generated and cognitively debriefed. Psychometric validation included factor analysis, item response theory analysis, and assessment of psychometric characteristics for the TRIM-HYPO.

RESULTS

Eight clinical experts and 167 patients participated in concept elicitation. The validation study included 407 patients. Thirteen of the 46 items from the preliminary measure were dropped due to ceiling/floor effects and high correlations between conceptually similar items. Factor analysis confirmed five domains in the TRIM-HYPO: daily function, emotional well-being, diabetes management, sleep disruption, and work productivity. All scores were internally consistent (0.86-0.95) and reproducible with a test-retest range of 0.75-0.98. All but one a priori hypothesized associations for validity were confirmed.

CONCLUSIONS

Study findings demonstrate that the final, 33-item TRIM-HYPO is reliable and valid and may be useful for assessing impacts related to NSHEs in research and clinical practice.

The psychosocial and financial impact of non-severe hypoglycemic events on people with diabetes: two international surveys

OBJECTIVES

To understand the impact of nocturnal and daytime non-severe hypoglycemic events on healthcare systems, work productivity and quality of life in people with type 1 or type 2 diabetes.

METHODS

People with diabetes who experienced a non-severe hypoglycemic event in the 4 weeks prior to the survey were eligible to participate in a nocturnal and/or daytime hypoglycemia survey. Surveys were conducted in Argentina, Australia, Brazil, Israel, Mexico and South Africa.

RESULTS

In total, 300 respondents were included in nocturnal/daytime hypoglycemia surveys (50/participating country/survey). All respondents with type 1 diabetes and 68%/62% (nocturnal/daytime) with type 2 diabetes were on insulin treatment. After an event, 25%/30% (nocturnal/daytime) of respondents decreased their insulin dose and 39%/36% (nocturnal/daytime) contacted a healthcare professional. In the week after an event, respondents performed an average of 5.6/6.4 (nocturnal/daytime) additional blood glucose tests. Almost half of the respondents (44%) reported that the event had a high impact on the quality of their sleep. Among nocturnal survey respondents working for pay, 29% went to work late, 16% left work early and 12% reported missing one or more full work days due to the surveyed event. In addition, 50%/39% (nocturnal/daytime) indicated that the event had a high impact on their fear of future hypoglycemia.

CONCLUSIONS

The findings suggest that nocturnal and daytime non-severe hypoglycemic events have a large financial and psychosocial impact. Diabetes management that minimizes hypoglycemia while maintaining good glycemic control may positively impact upon the psychological wellbeing of people with diabetes, as well as reducing healthcare costs and increasing work productivity.

Artificial pancreas: fuzzy logic and control of glycemia

PURPOSE OF REVIEW

This review describes the latest efforts, challenges, and experience of using automated insulin delivery systems at outpatient settings and home studies. This is an important step in getting recognition of these systems as a routine therapy for patients with type 1 diabetes.

RECENT FINDINGS

Almost 3 years elapsed since the first description of closed-loop use outside the protecting environment of the hospital, at a diabetes camp. In this period, several different approaches of closed-loop systems were used at outpatient settings. The low-glucose suspend feature on the pump showed a reduction in the risk of nocturnal hypoglycemia. Closed-loop systems with diverse control algorithms with a single or bihormonal approach showed an improvement in glycemic control. The improvement was demonstrated during the overnight use and during the 24-h use. The outpatient studies with closed-loop systems, especially overnight at home, demonstrated that the current configurations are already safe and efficient for daily use. Technological advancement should undoubtedly lead to even better performance.

SUMMARY

Studies using closed-loop systems at patients' home are currently being carried out. The preliminary results of these experiments are encouraging and enhance our confidence in this tool as suitable for use in clinical daily practice.

The Impact of Nocturnal Hypoglycemia on Clinical and Cost-Related Issues in Patients With Type 1 and Type 2 Diabetes

PURPOSE

This article provides an overview of the clinical and economic issues associated with hypoglycemia in patients with type 1 and type 2 diabetes mellitus. Current research regarding hypoglycemia is comprehensively reviewed, with special emphasis on nocturnal hypoglycemia, as almost 50% of all severe hypoglycemic episodes occur at nighttime during sleep. Current findings on the economic and human burden of hypoglycemia are presented.

CONCLUSIONS

Poor diabetes self-management leads to an increased risk for hypoglycemia and the development of long-term complications associated with poor glycemic control. Hypoglycemia is also associated with increased health care costs and resources required to treat hypoglycemic events, as well as personal financial costs and loss of productivity at school or work. In addition, fear, anxiety, and worry about hypoglycemic episodes are shown to interfere with patients' quality of life. Nocturnal hypoglycemia can cause a number of immediate clinical consequences, including convulsions, coma, and even death. Repeated long-term exposure to nocturnal hypoglycemia can blunt counterregulatory mechanisms that maintain glucose levels, leading to reduced cognitive function, impaired awareness of hypoglycemia, and hypoglycemia-associated autonomic failure. Clinicians must be aware of the impact of hypoglycemia, particularly nocturnal hypoglycemia, so that they can prescribe appropriate glucose-lowering therapy and educate patients about the prevention and management of hypoglycemic events to reduce anxiety and improve quality of life.

Chronic fatigue in type 1 diabetes: highly prevalent but not explained by hyperglycemia or glucose variability

OBJECTIVE Fatigue is a classical symptom of hyperglycemia, but the relationship between chronic fatigue and diabetes has not been systematically studied. We investigated prevalence, impact, and potential determinants of chronic fatigue in patients with type 1 diabetes mellitus (T1DM). RESEARCH DESIGN AND METHODS Out of 324 randomly selected T1DM outpatients, 214 participated in this cross-sectional observational study. Participants were compared with age- and sex-matched population-based controls. Chronic fatigue, functional impairments, current health status, comorbidity, diabetes-related factors, and fatigue-related cognitions and behaviors were assessed with questionnaires, and HbA1c values and comorbidity were assessed with medical records. Sixty-six patients underwent continuous glucose monitoring combined with an electronic fatigue diary for 5 days. Acute fatigue and four glucose parameters were determined: mean, variability, and relative time spent in hypoglycemia and hyperglycemia. RESULTS T1DM patients were significantly more often chronically fatigued (40%; 95% CI 34-47%) compared with matched controls (7%; 95% CI 3-10%; P < 0.001). Chronically fatigued patients had significantly more functional impairments. Fatigue was the most troublesome symptom. Age, depression, pain, sleeping problems, low self-efficacy concerning fatigue, and physical inactivity were significantly associated with chronic fatigue. Chronically fatigued patients spent slightly less time in hypoglycemia (proportion 0.07 ± 0.06 vs. 0.12 ± 0.10; P = 0.025). Glucose parameters were not related to acute fatigue. CONCLUSIONS Chronic fatigue is highly prevalent and clinically relevant in T1DM. Its significant relationship with cognitive behavioral variables and weak association with blood glucose levels suggests that behavioral interventions could be helpful in managing chronic fatigue in T1DM.

Insulin degludec compared with insulin glargine in insulin-naïve patients with type 2 diabetes: A 26-week, randomized, controlled, Pan-Asian, treat-to-target trial

Introduction

Insulin degludec (IDeg) is an ultra‐long‐acting basal insulin with a consistent action profile of >42 h. This trial compared the efficacy and safety of IDeg with insulin glargine (IGlar) in insulin‐naïve Asian patients with type 2 diabetes.

Materials and Methods

In this multinational, 26‐week, open‐label, treat‐to‐target trial, 435 participants (202 females, 233 males; mean age 58.6 years; mean body mass index 25 kg/m²; mean glycated hemoglobin [HbA_1c] 8.5%) were randomized (2:1) to IDeg or IGlar, each administered once daily with ≥1 oral antidiabetic drug(s) (OAD).

Results

After 26 weeks, HbA_1c had decreased by 1.24 and 1.35% in the IDeg and IGlar groups, respectively (treatment difference [IDeg – IGlar] 0.11%, 95% confidence interval [CI] −0.03 to 0.24), confirming non‐inferiority. Rates of overall confirmed hypoglycemia were similar for IDeg and IGlar during the full trial period (3.0 vs 3.7 episodes/patient‐year of exposure [PYE]; rate ratio [RR] 0.82, 95% CI 0.60 to 1.11, P = 0.20), but significantly lower (by 37%) for IDeg during the maintenance period (from week 16 onward; RR 0.63, 95% CI 0.42 to 0.94, P = 0.02). No significant difference in the rate of nocturnal confirmed hypoglycemia was found between IDeg and IGlar in the full trial period (0.8 vs 1.2 episodes/PYE; RR 0.62, 95% CI 0.38 to 1.04, P = 0.07) or maintenance period (RR 0.52, 95% CI 0.27 to 1.00, P = 0.05). Adverse event rates were similar between treatments.

Conclusions

Initiating insulin therapy with IDeg in Asian patients with type 2 diabetes, inadequately controlled with OADs, provides similar improvements in long‐term glycemic control to IGlar, but at a significantly lower rate of overall confirmed hypoglycemia once stable glycemic control and insulin dosing are achieved. This trial was registered with www.clinicaltrials.gov (no. NCT01059799).

Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society

OBJECTIVE

To review the evidence about the impact of hypoglycemia on patients with diabetes that has become available since the past reviews of this subject by the American Diabetes Association and The Endocrine Society and to provide guidance about how this new information should be incorporated into clinical practice.

PARTICIPANTS

Five members of the American Diabetes Association and five members of The Endocrine Society with expertise in different aspects of hypoglycemia were invited by the Chair, who is a member of both, to participate in a planning conference call and a 2-day meeting that was also attended by staff from both organizations. Subsequent communications took place via e-mail and phone calls. The writing group consisted of those invitees who participated in the writing of the manuscript. The workgroup meeting was supported by educational grants to the American Diabetes Association from Lilly USA, LLC and Novo Nordisk and sponsorship to the American Diabetes Association from Sanofi. The sponsors had no input into the development of or content of the report.

EVIDENCE

The writing group considered data from recent clinical trials and other studies to update the prior workgroup report. Unpublished data were not used. Expert opinion was used to develop some conclusions.

CONSENSUS PROCESS

Consensus was achieved by group discussion during conference calls and face-to-face meetings, as well as by iterative revisions of the written document. The document was reviewed and approved by the American Diabetes Association's Professional Practice Committee in October 2012 and approved by the Executive Committee of the Board of Directors in November 2012 and was reviewed and approved by The Endocrine Society's Clinical Affairs Core Committee in October 2012 and by Council in November 2012.

CONCLUSIONS

The workgroup reconfirmed the previous definitions of hypoglycemia in diabetes, reviewed the implications of hypoglycemia on both short- and long-term outcomes, considered the implications of hypoglycemia on treatment outcomes, presented strategies to prevent hypoglycemia, and identified knowledge gaps that should be addressed by future research. In addition, tools for patients to report hypoglycemia at each visit and for clinicians to document counseling are provided.

Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society

OBJECTIVE

To review the evidence about the impact of hypoglycemia on patients with diabetes that has become available since the past reviews of this subject by the American Diabetes Association and The Endocrine Society and to provide guidance about how this new information should be incorporated into clinical practice.

PARTICIPANTS

Five members of the American Diabetes Association and five members of The Endocrine Society with expertise in different aspects of hypoglycemia were invited by the Chair, who is a member of both, to participate in a planning conference call and a 2-day meeting that was also attended by staff from both organizations. Subsequent communications took place via e-mail and phone calls. The writing group consisted of those invitees who participated in the writing of the manuscript. The workgroup meeting was supported by educational grants to the American Diabetes Association from Lilly USA, LLC and Novo Nordisk and sponsorship to the American Diabetes Association from Sanofi. The sponsors had no input into the development of or content of the report.

EVIDENCE

The writing group considered data from recent clinical trials and other studies to update the prior workgroup report. Unpublished data were not used. Expert opinion was used to develop some conclusions.

CONSENSUS PROCESS

Consensus was achieved by group discussion during conference calls and face-to-face meetings, as well as by iterative revisions of the written document. The document was reviewed and approved by the American Diabetes Association's Professional Practice Committee in October 2012 and approved by the Executive Committee of the Board of Directors in November 2012 and was reviewed and approved by The Endocrine Society's Clinical Affairs Core Committee in October 2012 and by Council in November 2012.

CONCLUSIONS

The workgroup reconfirmed the previous definitions of hypoglycemia in diabetes, reviewed the implications of hypoglycemia on both short- and long-term outcomes, considered the implications of hypoglycemia on treatment outcomes, presented strategies to prevent hypoglycemia, and identified knowledge gaps that should be addressed by future research. In addition, tools for patients to report hypoglycemia at each visit and for clinicians to document counseling are provided.

Non-severe nocturnal hypoglycemic events: experience and impacts on patient functioning and well-being

Purpose

Non-severe nocturnal hypoglycemic events (NSNHEs) are hypoglycemic events that occur during sleep but do not require medical assistance from another individual. This study was conducted to better understand the NSNHEs as patients actually experience them in their daily life, and how they impacted functioning and well-being.

Methods

Nine focus groups were held in four countries with diabetics (Type 1 and Type 2) who had experienced an NSNHE within the previous month: France (2 groups); Germany (2 groups); United Kingdom (2 groups); and United States (3 groups). These groups were audio-taped, translated to English where applicable, and analyzed thematically.

Results

Seventy-eight people with diabetes participated in the focus groups: 41 (53 %) were female and 37 (47 %) were male; 24 (31 %) had Type 1 diabetes, and 54 (69 %) had Type 2 diabetes. Participant reports were grouped into several major themes: next day effects, symptoms, sleep impacts, social impacts, corrective action, practical management, feelings about NSNHEs, and work impacts.

Conclusions

People with both Type 1 and Type 2 diabetes experience NSNHEs. The range of impact on these patients is wide, from very mild to severe with a majority of participants experiencing strong impacts that limit their daily functioning. This finding suggests that NSNHEs are more impactful than previously believed.

Insulin degludec, an ultra-longacting basal insulin, versus insulin glargine in basal-bolus treatment with mealtime insulin aspart in type 1 diabetes (BEGIN Basal-Bolus Type 1): a phase 3, randomised, open-label, treat-to-target non-inferiority trial

BACKGROUND

Intensive basal-bolus insulin therapy has been shown to improve glycaemic control and reduce the risk of long-term complications that are associated with type 1 diabetes mellitus. Insulin degludec is a new, ultra-longacting basal insulin. We therefore compared the efficacy and safety of insulin degludec and insulin glargine, both administered once daily with mealtime insulin aspart, in basal-bolus therapy for type 1 diabetes.

METHODS

In an open-label, treat-to-target, non-inferiority trial, undertaken at 79 sites (hospitals and centres) in six countries, adults (aged ≥18 years) with type 1 diabetes (glycated haemoglobin [HbA(1c)] ≤10% [86 mmol/mol]), who had been treated with basal-bolus insulin for at least 1 year, were randomly assigned in a 3:1 ratio, with a computer-generated blocked allocation sequence, to insulin degludec or insulin glargine without stratification by use of a central interactive response system. The primary outcome was non-inferiority of degludec to glargine, assessed as a reduction in HbA(1c) after 52 weeks, with the intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00982228.

FINDINGS

Of 629 participants, 472 were randomly assigned to insulin degludec and 157 to insulin glargine; all were analysed in their respective treatment groups. At 1 year, HbA(1c) had fallen by 0·40% points (SE 0·03) and 0·39% points (0·07), respectively, with insulin degludec and insulin glargine (estimated treatment difference -0·01% points [95% CI -0·14 to 0·11]; p<0·0001 for non-inferiority testing) and 188 (40%) and 67 (43%) participants achieved a target HbA(1c) of less than 7% (<53 mmol/mol). Rates of overall confirmed hypoglycaemia (plasma glucose <3·1 mmol/L or severe) were similar in the insulin degludec and insulin glargine groups (42·54 vs 40·18 episodes per patient-year of exposure; estimated rate ratio [degludec to glargine] 1·07 [0·89 to 1·28]; p=0·48). The rate of nocturnal confirmed hypoglycaemia was 25% lower with degludec than with glargine (4·41 vs 5·86 episodes per patient-year of exposure; 0·75 [0·59 to 0·96]; p=0·021). Overall serious adverse event rates (14 vs 16 events per 100 patient-years of exposure) were similar for the insulin degludec and insulin glargine groups.

INTERPRETATION

Insulin degludec might be a useful basal insulin for patients with type 1 diabetes because it provides effective glycaemic control while lowering the risk of nocturnal hypoglycaemia, which is a major limitation of insulin therapy.

FUNDING

Novo Nordisk.

The impact of hypoglycaemia on quality of life and related patient-reported outcomes in Type 2 diabetes: a narrative review

As a common side effect of insulin treatment for diabetes, hypoglycaemia is a constant threat and can have far-reaching and potentially devastating consequences, including immediate physical injury as well as more pervasive cognitive, behavioural and emotional effects. Moreover, as a significant limiting factor in achieving optimal glycaemic control, exposure to hypoglycaemia can influence diabetes self-management. Although hypoglycaemia is known to occur in Type 2 diabetes, its morbidity and impact on the individual are not well recognized. The aim of the current review is to examine published evidence to achieve a synthesis of the scope and significance of the potential detriment caused by hypoglycaemia to individuals with Type 2 diabetes. The implications of these observations for treatment and research have also been considered. A narrative review was performed of empirical papers published in English since 1966, reporting the effect of hypoglycaemia on quality of life and related outcomes (including generic and diabetes-specific quality of life, emotional well-being and health utilities) in Type 2 diabetes. Research demonstrates the potential impact of hypoglycaemia on the lives of people with Type 2 diabetes, from an association with depressive symptoms and heightened anxiety, to impairment of the ability to drive, work and function in ways that are important for quality of life. Few studies consider hypoglycaemia as an explanatory variable in combination with quality of life or related primary endpoints. As a consequence, there is a pressing need for high-quality research into the overall impact of hypoglycaemia on the lives of people with Type 2 diabetes.

Impact of nocturnal hypoglycemic events on diabetes management, sleep quality, and next-day function: results from a four-country survey

OBJECTIVES

Non-severe nocturnal hypoglycemic events (NSNHEs) may have a major impact on patients. The objective was to determine how NSNHEs affect diabetes management, sleep quality, functioning, and to assess if these impacts differ by diabetes type or country.

METHODS

An internet survey to adults with diabetes in the US, UK, Germany, and France.

RESULTS

Of 6756 screened respondents, 1086 reported an NSNHE in the past month. For this last event, respondents with type 2 required significantly more time than type 1 to recognize and respond to the event (1.5 vs 1.1 hours), 25.7% (T1) and 18.5% (T2) decreased their normal insulin dose due to their most recent NSNHE. All respondents were likely to take 1-2 additional self-monitored blood glucose measurements on the day following. NSNHEs were associated with a high proportion of respondents contacting a healthcare professional (18.6% T1, 27.8% T2) reporting they could not return to sleep at night (13.3% T1, 13.4% T2), and tiredness on the day following the event (71.2% for both). Of the respondents working for pay, 18.4% T1 and 28.1% T2 reported being absent from work due to the NSNHE, and a substantial proportion of respondents (8.7% T1, 14.4% T2) also reported missing a meeting or work appointment or not finishing a task on time. Compared with other countries, respondents from France may experience a more substantial impact on diabetes management and daily functioning following an NSNHE. Potential limitations in this study include recall and selection bias; however, these biases are not believed to have impacted findings in any meaningful way.

CONCLUSIONS

NSNHEs are associated with a substantial impact on diabetes management, sleep quality, and next-day functioning.

Carbohydrate administration and exercise performance: what are the potential mechanisms involved?

It is well established that carbohydrate (CHO) administration increases performance during prolonged exercise in humans and animals. The mechanism(s), which could mediate the improvement in exercise performance associated with CHO administration, however, remain(s) unclear. This review focuses on possible underlying mechanisms that could explain the increase in exercise performance observed with the administration of CHO during prolonged muscle contractions in humans and animals. The beneficial effect of CHO ingestion on performance during prolonged exercise could be due to several factors including (i) an attenuation in central fatigue; (ii) a better maintenance of CHO oxidation rates; (iii) muscle glycogen sparing; (iv) changes in muscle metabolite levels; (v) reduced exercise-induced strain; and (vi) a better maintenance of excitation-contraction coupling. In general, the literature indicates that CHO ingestion during exercise does not reduce the utilization of muscle glycogen. In addition, data from a meta-analysis suggest that a dose-dependent relationship was not shown between CHO ingestion during exercise and an increase in performance. This could support the idea that providing enough CHO to maintain CHO oxidation during exercise may not always be associated with an increase in performance. Emerging evidence from the literature shows that increasing neural drive and attenuating central fatigue may play an important role in increasing performance during exercise with CHO supplementation. In addition, CHO administration during exercise appears to provide protection from disrupted cell homeostasis/integrity, which could translate into better muscle function and an increase in performance. Finally, it appears that during prolonged exercise when the ability of metabolism to match energy demand is exceeded, adjustments seem to be made in the activity of the Na+/K+ pump. Therefore, muscle fatigue could be acting as a protective mechanism during prolonged contractions. This could be alleviated when CHO is administered resulting in the better maintenance of the electrical properties of the muscle fibre membrane. The mechanism(s) by which CHO administration increases performance during prolonged exercise is(are) complex, likely involving multiple factors acting at numerous cellular sites. In addition, due to the large variation in types of exercise, durations, intensities, feeding schedules and CHO types it is difficult to assess if the mechanism(s) that could explain the increase in performance with CHO administration during exercise is(are) similar in different situations. Experiments concerning the identification of potential mechanism(s) by which performance is increased with CHO administration during exercise will add to our understanding of the mechanism(s) of muscle/central fatigue. This knowledge could have significant implications for improving exercise performance.

Sleep and the response to hypoglycaemia

Undetected nocturnal hypoglycaemia frequently occurs in patients with diabetes, having a negative influence on well-being, counterregulation against and awareness of subsequent hypoglycaemia, and even causing sudden death in some cases most likely by inducing cardiac arrhythmia. Sleep markedly weakens the neuroendocrine defence mechanism against hypoglycaemia by shifting the glycaemic threshold for counterregulatory activation to lower levels. While hypoglycaemia triggers awakening in healthy subjects, patients with type 1 diabetes frequently fail to awake in the presence of low plasma glucose levels. Little is known about the frequency of and responses to nocturnal hypoglycaemia in patients with type 2 diabetes. Unfortunately, effective strategies to prevent or even safely detect nocturnal hypoglycaemia are still lacking. Taken together, hypoglycaemia occurring during sleep presents a major, often neglected problem in the management of diabetic patients. Different aspects of this phenomenon such as responses to and consequences of nocturnal hypoglycaemia as well as strategies for its prevention are highlighted in this review.

Blood glucose levels and performance in a sports cAMP for adolescents with type 1 diabetes mellitus: a field study

Background. Acute hypo- and hyperglycemia causes cognitive and psychomotor impairment in individuals with type 1 diabetes mellitus (T1DM) that may affect sports performance. Objective. To quantify the effect of concurrent and antecedent blood glucose concentrations on sports skills and cognitive performance in youth with T1DM attending a sports camp. Design/Methods. 28 youth (ages 6-17 years) attending a sports camp carried out multiple skill-based tests (tennis, basketball, or soccer skills) with glucose monitoring over 4 days. Glucose levels at the time of testing were categorized as (a) hypoglycemic (<3.6 mM); (b) within an acceptable glycemic range (3.6-13.9 mM); or (c) hyperglycemic (>13.9 mM). Results. Overall, sports performance skill was approximately 20% lower when glucose concentrations were hypoglycemic compared to either acceptable or hyperglycemic at the time of skill testing (P < .05). During Stroop testing, "reading" and "color recognition" also degraded during hypoglycemia, while "interference" scores improved (P < .05). Nocturnal hypoglycemia was present in 66% of subjects, lasting an average of 84 minutes, but this did not affect sports skill performance the following day. Conclusions. Mild hypoglycemia markedly reduces sports skill performance and cognition in young athletes with T1DM.

Fatigue in patients with diabetes: a review

OBJECTIVE

Fatigue is a common and distressing complaint among people with diabetes and likely to hinder the ability to perform daily diabetes self-management tasks. A review of the literature about diabetes-related fatigue was conducted with an eye toward creating a framework for beginning to conduct more focused studies on this subject.

METHODS

A literature search containing the terms diabetes, fatigue, tiredness, and symptoms was conducted to search for literature that addressed diabetes-related fatigue.

RESULTS

Diabetes presents many potential pathways for fatigue, but focused studies on this symptom are rare. Furthermore, research on diabetes-related fatigue is limited by fatigue's nonspecific symptoms and because fatigue researchers have yet to agree on standardized definition, measurement, or diagnostic criteria. Additionally, few diabetes randomized clinical trials included measurement of patient-reported outcomes, such as symptoms or health-related quality of life in their study designs, although one that did provided some meaningful finding that symptom-focused education improved self-management practices, Hb(A1c) levels, quality of life, and symptom distress.

CONCLUSION

There is a need to standardize the definition, measurement, and diagnostic criteria of fatigue in diabetes. We present a model that can guide focused studies on fatigue in diabetes. The model capitalizes on the multidimensional phenomena (physiological, psychological, and lifestyle) associated with fatigue in diabetes.

Hypoglycemia during sleep impairs consolidation of declarative memory in type 1 diabetic and healthy humans

OBJECTIVE

Early nocturnal sleep enhances the consolidation of declarative memories acquired during prior wakefulness. Patients with type 1 diabetes frequently experience hypoglycemic episodes during sleep. We investigated whether short-lasting hypoglycemia during early nocturnal sleep affects the sleep-associated consolidation of declarative memories.

RESEARCH DESIGN AND METHODS

Sixteen type 1 diabetic patients and 16 healthy subjects matched for age and BMI were tested. On one condition, a linear fall of plasma glucose to 2.2 mmol/l was induced within 60 min by infusing insulin during early sleep. On the control condition, euglycemia (>3.86 mmol/l) was maintained throughout the night. In the morning, subjects recalled word pairs learned in the preceding evening. To assess mood and attention, a symptom questionnaire, an adjective check list, and the Stroop test were applied. Also, auditory event-related brain potentials were recorded.

RESULTS

After euglycemia, subjects recalled 1.5 +/- 0.5 more word pairs than after hypoglycemia (P < 0.01), remembering 2.0 +/- 0.6 more word pairs than at immediate recall before sleep (P = 0.002). Across the hypoglycemic night, no such gain occurred (+0.5 +/- 0.6 words; P = 0.41). Hypoglycemia during sleep also impaired mood (P < 0.05) but did not affect attention. Effects compared well between type 1 diabetic patients and healthy control subjects.

CONCLUSIONS

Our findings indicate specific sensitivity of declarative memory consolidation during sleep to rather short episodes of mild hypoglycemia. This effect may disable memory processing in type 1 diabetic patients prone to nocturnal hypoglycemic episodes and underlines the importance of considering sleep as a critical period in the treatment of these patients.

Nocturnal hypoglycaemia in type 1 diabetes--consequences and assessment

Hypoglycaemia is inevitable when striving for low HbA1c values. Nocturnal hypoglycaemia often occurs without symptoms, but results in diminished next day well-being and hypoglycaemia unawareness. Frequency of nocturnal hypoglycaemia was first assessed in research ward settings, but suffered from insufficient glucose sampling frequency. This may have resulted in overestimation of the duration of hypoglycaemic episodes. The advent of the first continuous glucose sensor, the needle-type MedtronicMiniMed Continuous Glucose Measurement System, revolutionized the assessment of glucose values. However, on scrutiny, the first version of this sensor showed a drift into the hypoglycaemic area and delayed recovery from hypoglycaemia. Using the microdialysis-based GlucoDay system, our group reported a lower frequency of nocturnal hypoglycaemia in type 1 diabetes patients using an insulin pump, than that expected from the existing literature. Today, more than 80 years after the introduction of insulin for the treatment of type 1 diabetes, the associated frequency of nocturnal hypoglycaemia still awaits its definitive assessment.

Controlling diabetes: the need for intensive therapy and barriers in clinical management

Although diabetes is a manageable condition, its prevalence worldwide has increased dramatically in the previous four decades. The principal goal of diabetes management is to prevent the microvascular and macrovascular complications of the disorder, which are associated with elevated blood glucose levels. Many large-scale clinical trials have demonstrated the benefits of intensive therapy regimens in lowering hemoglobin A(1c) (HbA(1c)) levels. However, despite detailed guidelines issued by several major international diabetes organisations, we are largely failing to reach their recommended target HbA(1c) levels. Although there have been many recent therapeutic advances for treatment of diabetes, three issues have emerged that affect the success of intensive therapy--hypoglycemia, weight gain, and physician-reluctance. Regardless of specific therapeutic regimens, each of these barriers in clinical management must be addressed individually and collectively if we are to effect change in disease outcomes for persons with diabetes.

Morbidity of hypoglycemia in type 1 diabetes

Hypoglycemia is a common side effect of intensive insulin therapy in patients with type 1 diabetes. Mild hypoglycemia is any episode that can be self-treated, while a severe episode requires external help for recovery. Acute hypoglycemia produces autonomic and neuroglycopenic symptoms, including cognitive impairment and mood changes, while sympathoadrenal stimulation can provoke acute hemodynamic changes with alterations in regional vascular perfusion and a risk of cardiac dysrhythmias. Neurological manifestations include coma, convulsions and focal abnormalities. Long-term morbidities associated with hypoglycemia include impaired awareness of hypoglycemia, counterregulatory hormonal deficiencies, hypoglycemia-associated autonomic failure, and, in rare cases, permanent cognitive impairment. Hypoglycemia affects all aspects of life for the person with type 1 diabetes, including employment, social interactions, driving, sport and leisure activities, and sleep. Appreciation of the potential morbidities of hypoglycemia should encourage physicians to utilize therapeutic regimens that decrease the risk of severe hypoglycemia.

Nocturnal hypoglycemia: clinical manifestations and therapeutic strategies toward prevention

OBJECTIVE

To review the features of nocturnal hypoglycemia and various preventive strategies.

METHODS

We discuss the physiologic changes, the potential precipitating factors, the immediate and long-term effects, and the currently available options for treatment of nocturnal hypoglycemia in patients with diabetes.

RESULTS

Nocturnal hypoglycemia is common in patients with type 1 diabetes and is usually asymptomatic. Nocturnal hyperinsulinemia frequently occurs with insulin therapy, and although blood glucose levels are often low during sleep, they are seldom measured routinely. Almost 50% of all episodes of severe hypoglycemia occur at night during sleep. Such episodes can cause convulsions and coma and have been implicated as a precipitating factor in cardiac arrhythmias resulting in sudden death--the "dead-in-bed syndrome." Nocturnal hypoglycemia seems to have no immediate detrimental effect on cognitive function; however, on the following day, mood and well-being may be adversely affected. Recurrent exposure to nocturnal hypoglycemia may impair cognitive function; other substantial long-term morbidity includes the development of acquired hypoglycemia syndromes, such as impaired awareness of hypoglycemia, through the putative effect of unsuspected recurrent episodes of nocturnal hypoglycemia.

CONCLUSION

In efforts to decrease the risk of nocturnal hypoglycemic episodes, various strategies can be used to minimize the nocturnal hyperinsulinemia that is associated with many insulin replacement regimens. Regular blood glucose monitoring (particularly at bedtime), the ingestion of appropriate bedtime snacks, and the utilization of short- and long-acting insulin analogues may all help to prevent or minimize the frequency of nocturnal hypoglycemia.

Local energy depletion in the basal forebrain increases sleep

Sleep saves energy, but can brain energy depletion induce sleep? We used 2,4-dinitrophenol (DNP), a molecule which prevents the synthesis of ATP, to induce local energy depletion in the basal forebrain of rats. Three-hour DNP infusions induced elevations in extracellular concentrations of lactate, pyruvate and adenosine, as well as increases in non-REM sleep during the following night. Sleep was not affected when DNP was administered to adjacent brain areas, although the metabolic changes were similar. The amount and the timing of the increase in non-REM sleep, as well as in the concentrations of lactate, pyruvate and adenosine with 0.5-1.0 mM DNP infusion, were comparable to those induced by 3 h of sleep deprivation. Here we show that energy depletion in localized brain areas can generate sleep. The energy depletion model of sleep induction could be applied to in vitro research into the cellular mechanisms of prolonged wakefulness.