Gut hormones and appetite regulation

PURPOSE OF REVIEW

Various gut hormones interact with the brain through delicate communication, thereby influencing appetite and subsequent changes in body weight. This review summarizes the effects of gut hormones on appetite, with a focus on recent research.

RECENT FINDINGS

Ghrelin is known as an orexigenic hormone, whereas glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), postprandial peptide YY (PYY), and oxyntomodulin (OXM) are known as anorexigenic hormones. Recent human studies have revealed that gut hormones act differently in various systems, including adipose tissue, beyond appetite and energy intake, and even involve in high-order thinking. Environmental factors including meal schedule, food contents and quality, type of exercise, and sleep deprivation also play a role in the influence of gut hormone on appetite, weight change, and obesity. Recently published studies have shown that retatrutide, a triple-agonist of GLP-1, GIP, and glucagon receptor, and orforglipron, a GLP-1 receptor partial agonist, are effective in weight loss and improving various metabolic parameters associated with obesity.

SUMMARY

Various gut hormones influence appetite, and several drugs targeting these receptors have been reported to exert positive effects on weight loss in humans. Given that diverse dietary and environmental factors affect the actions of gut hormones and appetite, there is a need for integrated and largescale long-term studies in this field.

Efficacy and Safety of Alogliptin-Pioglitazone Combination for Type 2 Diabetes Mellitus Poorly Controlled with Metformin: A Multicenter, Double-Blind Randomized Trial

Background

Guidelines for switching to triple combination therapy directly after monotherapy failure are limited. This study investigated the efficacy, long-term sustainability, and safety of either mono or dual add-on therapy using alogliptin and pioglitazone for patients with type 2 diabetes mellitus (T2DM) who did not achieve their target glycemic range with metformin monotherapy.

Methods

The Practical Evidence of Antidiabetic Combination Therapy in Korea (PEAK) was a multicenter, placebo-controlled, double-blind, randomized trial. A total of 214 participants were randomized to receive alogliptin+pioglitazone (Alo+Pio group, n=70), alogliptin (Alo group, n=75), or pioglitazone (Pio group, n=69). The primary outcome was the difference in glycosylated hemoglobin (HbA1c) levels between the three groups at baseline to 24 weeks. For durability, the achievement of HbA1c levels <7% and <6.5% was compared in each group. The number of adverse events was investigated for safety.

Results

After 24 weeks of treatment, the change of HbA1c in the Alo+Pio, Alo, and Pio groups were -1.38%±0.08%, -1.03%±0.08%, and -0.84%±0.08%, respectively. The Alo+Pio group had significantly lower HbA1c levels than the other groups (P=0.0063, P<0.0001) and had a higher proportion of patients with target HbA1c achievement. In addition, insulin sensitivity and β-cell function, lipid profiles, and other metabolic indicators were also improved. There were no significant safety issues in patients treated with triple combination therapy.

Conclusion

Early combination triple therapy showed better efficacy and durability than the single add-on (dual) therapy. Therefore, combination therapy with metformin, alogliptin, and pioglitazone is a valuable early treatment option for T2DM poorly controlled with metformin monotherapy.

Remnant cholesterol is an independent risk factor for the incidence of chronic kidney disease in newly-diagnosed type 2 diabetes: A nationwide population-based study

AIMS

To evaluate the impact of remnant cholesterol (remnant-C) on chronic kidney disease (CKD) incidence in newly-diagnosed type 2 diabetes.

METHODS

This retrospective cohort study used Korean National Health Insurance Service data on 212,836 patients with newly-diagnosed type 2 diabetes between 2009 and 2014. We conducted cox regression analysis to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for developing CKD according to remnant-C tertile.

RESULTS

During a median follow-up duration of 5.23 years, 6,850 CKD cases developed. In the fully adjusted model, HRs and 95 % CIs for incident CKD increased in the highest tertile of baseline remnant-C compared to the lowest (HR [95 % CI]; 1.234 [1.159-1.314]). This association was more prominent in patients with hypertension or low-income status (P for interaction < 0.05). Increased HRs in the highest tertile of remnant-C was sustained in type 2 diabetes patients within target range of conventional lipid profile such as low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL and < 70 mg/dL (1.165 [1.041-1.304] and 1.308 [1.063-1.609]), high-density lipoprotein cholesterol (HDL-C) (1.243 [1.155-1.338]) and triglyceride (1.168 [1.076-1.268]), respectively.

CONCLUSIONS

In newly-diagnosed type 2 diabetes patients, higher remnant-C is independently associated with CKD incidence, even when conventional lipid values are well-controlled.

Attention to Innate Circadian Rhythm and the Impact of Its Disruption on Diabetes

Novel strategies are required to reduce the risk of developing diabetes and/or clinical outcomes and complications of diabetes. In this regard, the role of the circadian system may be a potential candidate for the prevention of diabetes. We reviewed evidence from animal, clinical, and epidemiological studies linking the circadian system to various aspects of the pathophysiology and clinical outcomes of diabetes. The circadian clock governs genetic, metabolic, hormonal, and behavioral signals in anticipation of cyclic 24-hour events through interactions between a "central clock" in the suprachiasmatic nucleus and "peripheral clocks" in the whole body. Currently, circadian rhythmicity in humans can be subjectively or objectively assessed by measuring melatonin and glucocorticoid levels, core body temperature, peripheral blood, oral mucosa, hair follicles, rest-activity cycles, sleep diaries, and circadian chronotypes. In this review, we summarized various circadian misalignments, such as altered light-dark, sleep-wake, rest-activity, fasting-feeding, shift work, evening chronotype, and social jetlag, as well as mutations in clock genes that could contribute to the development of diabetes and poor glycemic status in patients with diabetes. Targeting critical components of the circadian system could deliver potential candidates for the treatment and prevention of type 2 diabetes mellitus in the future.

Ischaemic stroke in patients with diabetes requiring urgent procedures during the COVID-19 pandemic in South Korea: a retrospective, nationwide, population-based cohort study using data from the National Emergency Department Information System

OBJECTIVES

The COVID-19 pandemic resulted in suboptimal care for ischaemic stroke. Patients with diabetes mellitus (DM), a high-risk group for stroke, had compromised routine care during the pandemic, which increases the chance of stroke. We examined influence of the COVID-19 pandemic on the management of ischaemic stroke in patients with DM in South Korea.

DESIGN

Retrospective, nationwide, population-based cohort study.

SETTING

Data from the National Emergency Department Information System.

PARTICIPANTS

We analysed 11 734 patients diagnosed with acute ischaemic stroke who underwent intravenous thrombolysis or endovascular thrombectomy between 2019 (the reference year) and 2020 (the pandemic year). Among them, 1014 subjects with DM were analysed separately.

OUTCOME MEASURES

The frequency of emergency department (ED) visits, time from symptom onset to ED, from ED visit to admission and in-hospital mortality were compared between two periods in the overall population and in patients with DM.

RESULTS

During the pandemic, the incidence of ischaemic stroke requiring urgent procedures increased by 7.57% in total and by 9.03% in patients with DM. Time delay from symptom onset to ED (reference vs pandemic, total: 1.50 vs 1.55 hours; p<0.01) and from ED visit to admission (total: 3.88 vs 3.92 hours; p=0.02) occurred during the pandemic in the overall population, but not significantly in patients with DM specifically. Older patients with DM showed higher chances of intensive care unit (ICU) admission during the pandemic: 53.5% vs 62.8% in age 70-79, 60.5% vs 71.9% in age 80-89 and 20.0% vs 70.8% in age ≥90 years (all p=0.01). There was no significant difference in in-hospital mortality between two periods (total: 8.2% vs 8.4%, p=0.65; DM: 8.1% vs 6.7%, p=0.25).

CONCLUSIONS

During the COVID-19 pandemic, the incidence of ischaemic stroke requiring urgent procedures increased, and older patients with DM showed a higher ICU admission rate. However, the pandemic was not associated with an increased in-hospital stroke mortality.

AM1638, a GPR40-Full Agonist, Inhibited Palmitate- Induced ROS Production and Endoplasmic Reticulum Stress, Enhancing HUVEC Viability in an NRF2-Dependent Manner

BACKGRUOUND

G protein-coupled receptor 40 (GPR40) is a key molecule in diabetes and fatty liver, but its role in endothelial dysfunction remains unclear. Our objective in this study was to determine whether GPR40 agonists protect endothelial cells against palmitatemediated oxidative stress.

METHODS

Human umbilical vein endothelial cells (HUVECs) were used to investigate effects of various GPR40 agonists on vascular endothelium.

RESULTS

In HUVECs, AM1638, a GPR40-full agonist, enhanced nuclear factor erythroid 2-related factor 2 (NRF2) translocation to the nucleus and heme oxygenase-1 (HO-1) expression, which blocked palmitate-induced superoxide production. Those antioxidant effects were not detected after treatment with LY2922470 or TAK875, GPR40-partial agonists, suggesting that GPR40 regulates reactive oxygen species (ROS) removal in a ligand-dependent manner. We also found that palmitate-induced CCAAT/enhancer-binding protein homologous protein expression; X-box binding protein-1 splicing, nuclear condensation, and fragmentation; and caspase-3 cleavage were all blocked in an NRF2-dependent manner after AM1638 treatment. Both LY2922470 and TAK875 also improved cell viability independent of the NRF2/ROS pathway by reducing palmitate-mediated endoplasmic reticulum stress and nuclear damage. GPR40 agonists thus have beneficial effects against palmitate in HUVECs. In particular, AM1638 reduced palmitate-induced superoxide production and cytotoxicity in an NRF2/HO-1 dependent manner.

CONCLUSION

GPR40 could be developed as a good therapeutic target to prevent or treat cardiovascular diseases such as atherosclerosis.

Clinical and Lifestyle Determinants of Continuous Glucose Monitoring Metrics in Insulin-Treated Patients with Type 2 Diabetes Mellitus

BACKGRUOUND

There was limited evidence to evaluate the association between lifestyle habits and continuous glucose monitoring (CGM) metrics. Thus, we aimed to depict the behavioral and metabolic determinants of CGM metrics in insulin-treated patients with type 2 diabetes mellitus (T2DM).

METHODS

This is a prospective observational study. We analyzed data from 122 insulin-treated patients with T2DM. Participants wore Dexcom G6 and Fitbit, and diet information was identified for 10 days. Multivariate-adjusted logistic regression analysis was performed for the simultaneous achievement of CGM-based targets, defined by the percentage of time in terms of hyper, hypoglycemia and glycemic variability (GV). Intake of macronutrients and fiber, step counts, sleep, postprandial C-peptide-to-glucose ratio (PCGR), information about glucose lowering medications and metabolic factors were added to the analyses. Additionally, we evaluated the impact of the distribution of energy and macronutrient during a day, and snack consumption on CGM metrics.

RESULTS

Logistic regression analysis revealed that female, participants with high PCGR, low glycosylated hemoglobin (HbA1c) and daytime step count had a higher probability of achieving all targets based on CGM (odds ratios [95% confidence intervals] which were 0.24 [0.09 to 0.65], 1.34 [1.03 to 1.25], 0.95 [0.9 to 0.99], and 1.15 [1.03 to 1.29], respectively). And participants who ate snacks showed a shorter period of hyperglycemia and less GV compared to those without.

CONCLUSION

We confirmed that residual insulin secretion, daytime step count, HbA1c, and women were the most relevant determinants of adequate glycemic control in insulin-treated patients with T2DM. In addition, individuals with snack consumption were exposed to lower times of hyperglycemia and GV.

Additive impact of diabetes and sarcopenia on all-cause and cardiovascular mortality: A longitudinal nationwide population-based study

OBJECTIVE

Diabetes mellitus (DM) and sarcopenia (SP) are growing public health concerns in an aging society, which share common pathophysiological mechanisms and are associated with serious health consequences. We investigated the impact of DM and SP on all-cause and cardiovascular mortalities in a longitudinal nationwide population-based study.

METHODS

The study analyzed data from the Korea National Health and Nutrition Examination Survey conducted between 2008 and 2011, including information on appendicular skeletal muscle mass data. Mortality data up to December 2020 were retrieved from the National Death Registry.

RESULTS

Among the 17,920 participants, 14,737 (82.2 %) had neither DM nor SP (DM-/SP-), 1349 (7.5 %) had only DM (DM+/SP-), 1425 (8.0 %) had only SP (DM-/SP+), and 409 (2.3 %) had both DM and SP (DM+/SP+). Compared to the DM-/SP- group, the DM-/SP+ and DM+/SP+ groups demonstrated increased all-cause mortality with adjusted hazard ratios (HRs) of 1.47 (95 % confidence interval [CI]: 1.14-1.89) and 1.85 (95 % CI: 1.28-2.69), respectively, while the DM+/SP- group did not (HR 1.29, 95 % CI: 0.97-1.74). The DM+/SP+ group demonstrated the highest risk of overall mortality (p-for-trend <0.001). Compared to the DM-/SP- group, only the DM+/SP+ group demonstrated increased cardiovascular mortality with HRs of 2.10 (95 % CI: 1.11-4.00) while the DM+/SP- (HR 1.35, 95 % CI: 0.79-2.30) and DM-/SP+ (HR 1.42, 95 % CI: 0.84-2.43) groups did not.

CONCLUSIONS

The coexistence of DM and SP additively increased the risk of all-cause and cardiovascular mortality. Individuals with either disease may require more careful management to prevent the development of the other disease to reduce mortality.

Risk of type 2 diabetes mellitus in adult patients with atopic dermatitis

AIMS

This study aimed to investigate the subsequent risk of type 2 diabetes mellitus (T2D) in adults newly diagnosed with atopic dermatitis (AD).

METHODS

This propensity score-matching cohort study used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) 2.0 database in South Korea from 2002 to 2015. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox proportional hazards model, for the new onset of T2D (ICD-10 code, E11) in AD patients compared to the matched controls. Subgroup and sensitivity analyses were also conducted.

RESULTS

Each of the 36,692 individuals in the AD group and matched control group was included in the analysis. The risk of T2D in the AD group was significantly higher than that of the matched controls in the adjusted model (adjusted HR 1.44; 95% CI 1.27-1.63, P <.001). The results of subgroup analysis by sex, age, and body mass index were consistent with the results of the primary analysis. Sensitivity analyses using different T2D and/or AD definitions also showed consistent results.

CONCLUSIONS

The significant risk of subsequent T2D in adult AD patients suggested the necessity for efforts to prevent T2D in AD patients.

A Novel Anthropometric Parameter, Weight-Adjusted Waist Index Represents Sarcopenic Obesity in Newly Diagnosed Type 2 Diabetes Mellitus

Background

As the metabolic significance of sarcopenic obesity (SO) is revealed, finding an appropriate index to detect SO is important, especially for type 2 diabetes mellitus (T2DM) patients with accompanying metabolic dysfunction.

Methods

Participants (n=515) from the Korea Guro Diabetes Program were included to compare how well waist circumference (WC), waist hip ratio (WHR), waist height ratio (WHtR), and the weight-adjusted waist index (WWI) predict SO in newly diagnosed T2DM patients. Sarcopenia was defined based on guidelines from the 2019 Asian Working Group for Sarcopenia as both low muscle mass (appendicular skeletal muscle [ASM]/height² <7.0 kg/m² for men, <5.4 kg/m² for women) and strength (handgrip strength <28.0 kg for men, <18.0 kg for women) and/or reduced physical performance (gait speed <1.0 m/sec). Obesity was defined as a WC ≥90 cm in men and ≥85 cm in women. The WHR, WHtR, and WWI were calculated by dividing the WC by the hip circumference, height, and √ weight, respectively.

Results

The WC, WHR, and WHtR correlated positively with the fat and muscle mass represented by truncal fat amount (TFA) and ASM, whereas the WWI was proportional to the TFA and inversely related to ASM. Of the four tests, the WWI showed the highest area under the receiver operative characteristic curve for SO. The WWI also exhibited a positive correlation with albuminuria and the mean brachial-ankle pulse wave velocity, especially in patients aged ≥65 years.

Conclusion

The WWI is the preferable anthropometric index for predicting SO in T2DM patients, and it might be a proper index for predicting cardiometabolic risk factors in elderly people.

Interplay of skeletal muscle and adipose tissue: sarcopenic obesity

Sarcopenic obesity is becoming a global health concern, owing to the rising older population, causing cardiometabolic morbidity and mortality. Loss of muscle exceeding normal age-related changes has been revealed to be associated with obesity, aggravating each other through complex interactions. Physiological regeneration and proliferation of muscle tissue are achieved through harmonious processes of regulated inflammation, autophagy, muscle satellite cell proliferation, and signaling molecule function. Adipokines and myokines are signaling molecules from adipose tissue and muscle, respectively, that exert autocrine, paracrine, and endocrine effects on fat and muscle tissues. These signaling molecules interact with each other to regulate metabolic homeostasis. However, excessive adiposity creates pro-inflammatory conditions, leading to metabolic disorders and the disorganization of systemic homeostasis. Therefore, obesity impedes muscle tissue regeneration and induces the loss of muscle mass and function. Numerous studies have attempted to demonstrate the pathophysiological interaction between sarcopenia and obesity, but the interwoven matrix of the relationship between myokines and adipokines has made it difficult for researchers to understand them. This review briefly describes updated information about the crosstalk between muscle and adipose tissue.

Impact of diabetes on emergency care of acute myocardial infarction patients during the coronavirus disease 2019 pandemic: a nationwide population-based study

Background

Although acute myocardial infarction (AMI) requires timely intervention, limited nationwide data is available regarding the association between disruption of emergency services and outcomes of patients with AMI during the coronavirus disease 2019 (COVID-19) pandemic. Moreover, whether diabetes mellitus (DM) adversely affects disease severity in these patients has not yet been investigated.

Methods

This nationwide population-based study analyzed 45,648 patients with AMI, using data from the national registry of emergency departments (ED) in Korea. Frequency of ED visits and disease severity were compared between the COVID-19 outbreak period (year 2020) and the control period (the previous year 2019).

Results

The number of ED visits by patients with AMI decreased during the first, second, and third waves of the outbreak period compared to the corresponding time period in the control period (all p-values < 0.05). A longer duration from symptom onset to ED visit (p = 0.001) and ED stay (p = 0.001) and higher rates of resuscitation, ventilation care, and extracorporeal membrane oxygen insertion were observed during the outbreak period than during the control period (all p-values < 0.05). These findings were exacerbated in patients with comorbid DM; Compared to patients without DM, patients with DM demonstrated delayed ED visits, longer ED stays, more intensive care unit admissions (p < 0.001), longer hospitalizations (p < 0.001), and higher rates of resuscitation, intubation, and hemodialysis (all p-values < 0.05) during the outbreak period. While in-hospital mortality was similar in AMI patients with and without comorbid DM during the two periods (4.3 vs. 4.4%; p = 0.671), patients with DM who had other comorbidities such as chronic kidney disease or heart failure or were aged ≥ 80 years had higher in-hospital mortality compared with those without any of the comorbidities (3.1 vs. 6.0%; p < 0.001).

Conclusion

During the pandemic, the number of patients with AMI presenting to the ED decreased compared with that of the previous year, while the disease severity increased, particularly in patients with comorbid DM.

Association of long-term hyperglycaemia and insulin resistance with brain atrophy and cognitive decline: A longitudinal cohort study

AIM

To investigate the longitudinal changes in brain volume and cognitive function associated with diabetes at midlife, and to examine whether long-term hyperglycaemia, insulin resistance or secretory function is associated with brain atrophy and cognitive decline.

MATERIALS AND METHODS

We used data from 2377 participants with both baseline and 4-year follow-up brain magnetic resonance images and neuropsychological measures from the Ansan cohort of the Korean Genome Epidemiology Study. Time-weighted mean glycaemic values were calculated using all measurements over an average duration of 10.6 years from cohort initiation to baseline visits.

RESULTS

Type 2 diabetes was associated with greater white matter volume reduction (adjusted volume difference = -1.96 ml, 95% CI: -3.73, -0.18) and executive function decline (adjusted Z score difference = -0.14, 95% CI: -0.23, -0.05) during the follow-up period of 4.2 years. Decline of verbal and visual memory or verbal fluency was not associated with diabetes. Greater executive function decline was associated with higher time-weighted mean HbA1c level over the preceding 10.6 years (P < .001), but not with insulin resistance markers in the diabetes group. Participants with diabetes, whose time-weighted average HbA1c level was maintained above 6.5% over the previous decade, showed greater decline in executive function and global cognition than the normal glucose group.

CONCLUSIONS

Long-term hyperglycaemia was a major independent factor associated with rapid cognitive decline in middle-aged adults with diabetes. Maintaining ideal glucose levels in diabetes at midlife might prevent later rapid cognitive decline.

Hormonal Gut-Brain Signaling for the Treatment of Obesity

The brain, particularly the hypothalamus and brainstem, monitors and integrates circulating metabolic signals, including gut hormones. Gut-brain communication is also mediated by the vagus nerve, which transmits various gut-derived signals. Recent advances in our understanding of molecular gut-brain communication promote the development of next-generation anti-obesity medications that can safely achieve substantial and lasting weight loss comparable to metabolic surgery. Herein, we comprehensively review the current knowledge about the central regulation of energy homeostasis, gut hormones involved in the regulation of food intake, and clinical data on how these hormones have been applied to the development of anti-obesity drugs. Insight into and understanding of the gut-brain axis may provide new therapeutic perspectives for the treatment of obesity and diabetes.

Sleep Duration and the Risk of Type 2 Diabetes: A Community-Based Cohort Study with a 16-Year Follow-up

BACKGRUOUND

We aimed to investigate the moderating effects of obesity, age, and sex on the association between sleep duration and the development of diabetes in Asians.

METHODS

We analyzed data from a cohort of the Korean Genome and Epidemiology Study conducted from 2001 to 2020. After excluding shift workers and those with diabetes at baseline, 7,407 participants were stratified into three groups according to sleep duration: ≤5 hours/night, >5 to 7 hours/night (reference), and >7 hours/night. The Cox proportional hazards analyses were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident type 2 diabetes mellitus (T2DM). Subgroup analyses were performed according to obesity, age, and sex.

RESULTS

During 16 years of follow-up, 2,024 cases of T2DM were identified. Individuals who slept ≤5 h/night had a higher risk of incident diabetes than the reference group (HR, 1.17; 95% CI, 1.02 to 1.33). The subgroup analysis observed a valid interaction with sleep duration only for obesity. A higher risk of T2DM was observed in the ≤5 hours/night group in non-obese individuals, men, and those aged <60 years, and in the >7 hours/night group in obese individuals (HRs were 1.34 [95% CI, 1.11 to 1.61], 1.22 [95% CI, 1 to 1.49], and 1.18 [95% CI, 1.01 to 1.39], respectively).

CONCLUSION

This study confirmed the effect of sleep deprivation on the risk of T2DM throughout the 16-year follow-up period. This impact was confined to non-obese or young individuals and men. We observed a significant interaction between sleep duration and obesity.

Evaluation and Management of Patients With Diabetes and Heart Failure: A Korean Diabetes Association and Korean Society of Heart Failure Consensus Statement

Diabetes mellitus is a major risk factor for the development of heart failure. Furthermore, the prognosis of heart failure is worse in patients with diabetes mellitus than in those without it. Therefore, early diagnosis and proper management of heart failure in patients with diabetes mellitus are important. This review discusses the current criteria for diagnosis and screening tools for heart failure and the currently recommended pharmacological therapies for heart failure. We also highlight the effects of anti-diabetic medications on heart failure.

Evaluation and Management of Patients with Diabetes and Heart Failure: A Korean Diabetes Association and Korean Society of Heart Failure Consensus Statement

Diabetes mellitus is a major risk factor for the development of heart failure. Furthermore, the prognosis of heart failure is worse in patients with diabetes mellitus than in those without it. Therefore, early diagnosis and proper management of heart failure in patients with diabetes mellitus are important. This review discusses the current criteria for diagnosis and screening tools for heart failure and the currently recommended pharmacological therapies for heart failure. We also highlight the effects of anti-diabetic medications on heart failure.

Anagliptin twice-daily regimen improves glycaemic variability in subjects with type 2 diabetes: A double-blind, randomized controlled trial

AIM

To determine whether the twice-daily (BID) regimen is superior to the once-daily (QD) regimen for managing glycaemic variability by comparing the effects of anagliptin 100 mg BID versus sitagliptin 100 mg QD.

MATERIALS AND METHODS

A double-blinded, randomized, multicentre study was performed in 89 patients with type 2 diabetes treated with metformin alone (6.5% < HbA1c < 8.5%). Subjects were randomly assigned to anagliptin 100 mg BID or sitagliptin 100 mg QD in a 1:1 ratio for 12 weeks. Continuous glucose monitoring was used to measure the mean amplitude of glycaemic excursion (MAGE) and postprandial time in range (TIR) before and after dipeptidyl peptidase-4 (DPP-4) inhibitor treatment to compare glycaemic variability.

RESULTS

The decrease from baseline in MAGE at 12 weeks after DPP-4 inhibitor treatment was significantly greater in the anagliptin BID group than in the sitagliptin QD group (P < .05); -30.4 ± 25.6 mg/dl (P < .001) in the anagliptin group versus -9.5 ± 38.0 mg/dl (P = .215) in the sitagliptin group. The TIR after dinner increased by 33.0% ± 22.0% (P < .001) in the anagliptin group and by 14.6% ± 28.2% (P = .014) in the sitagliptin group, with a statistically significant difference (P = .009). No statistically significant differences were observed between the groups in the changes in HbA1c and fasting plasma glucose (FPG).

CONCLUSIONS

The anagliptin BID regimen for the treatment of type 2 diabetes was superior in blood glucose control after dinner to improve glycaemic variability, as indicated by MAGE and TIR, but was equivalent to the QD regimen in terms of HbA1c and FPG.

Association of plasma brain-derived neurotrophic factor levels and frailty in community-dwelling older adults

Brain-derived neurotrophic factor (BDNF), an exercise-induced neurotrophin, is an important factor in memory consolidation and cognitive function. This study evaluates the association between plasma BDNF levels and frailty in community-dwelling older adults. Plasma BDNF levels were analyzed in a total of 302 individuals aged 70-84 years from the Korean Frailty and Aging Cohort Study. There were 30 (9.9%) participants with frailty. They were older and had a higher prevalence of dementia and depression than those without frailty. There were no differences in the proportion of male sex between the frail and non-frail groups. Plasma BDNF levels were significantly lower in participants with frailty than in those without frailty. The presence of frailty was significantly associated with plasma BDNF levels (odds ratio 0.508, 95% confidence interval 0.304-0.849) as well as age, hemoglobin, and the presence of dementia, and depression. After adjustment for confounding factors, the significant association between plasma BDNF and frailty was maintained (0.495, 0.281-0.874). This association remained consistent after exclusion of individuals with dementia, depression, stroke, diabetes, and osteoporosis. Plasma BDNF levels were significantly associated with frailty in community-dwelling older adults. Our study may suggest the possible role of BDNF as a novel biomarker of frailty.

Comparison of Laser and Conventional Lancing Devices for Blood Glucose Measurement Conformance and Patient Satisfaction in Diabetes Mellitus

Self-monitoring of capillary blood glucose is important for controlling diabetes. Recently, a laser lancing device (LMT-1000) that can collect capillary blood without skin puncture was developed. We enrolled 150 patients with type 1 or 2 diabetes mellitus. Blood sampling was performed on the same finger on each hand using the LMT-1000 or a conventional lancet. The primary outcome was correlation between glucose values using the LMT-1000 and that using a lancet. And we compared the pain and satisfaction of the procedures. The capillary blood sampling success rates with the LMT-1000 and lancet were 99.3% and 100%, respectively. There was a positive correlation (r=0.974, P<0.001) between mean blood glucose levels in the LMT-1000 (175.8±63.0 mg/dL) and conventional lancet samples (172.5±63.6 mg/dL). LMT-1000 reduced puncture pain by 75.0% and increased satisfaction by 80.0% compared to a lancet. We demonstrated considerable consistency in blood glucose measurements between samples from the LMT-1000 and a lancet, but improved satisfaction and clinically significant pain reduction were observed with the LMT-1000 compared to those with a lancet.

Fasting Glucose Variability and the Risk of Dementia in Individuals with Diabetes: A Nationwide Cohort Study

BACKGROUND

We investigated whether fasting glucose (FG) variability could predict the risk of dementia.

METHODS

This cohort study analyzed data from Koreans with diabetes after at least three health examinations by the Korean National Health Insurance Corporation between 2005 and 2010, which included at least one examination between 2009 and 2010. A total of 769,554 individuals were included, excluding those aged <40 years and those with dementia. FG variability was measured using the variability independent of the mean (FG-VIM). The incidence of dementia was defined by the International Classification of Diseases 10th Revision codes and prescription of anti-dementia medication and was subdivided into Alzheimer's disease (AD) and vascular dementia (VD).

RESULTS

During the 6.9-year follow-up, 54,837, 41,032, and 6,892 cases of all-cause dementia, AD, and VD, respectively, were identified. Cox proportional regression analyses showed that as the FG-VIM quartile increased, the risk of dementia serially increased after adjustment for metabolic factors, income status, and diabetes-related characteristics, including the mean FG. Participants in FG-VIM quartile 4 showed a 18%, 19%, and 17% higher risk for all-cause dementia, AD, and VD, respectively, than those in quartile 1; this particularly included non-obese patients with a longer duration of diabetes, high FG levels, dyslipidemia, and those taking glucose-lowering medications. Conversely, the baseline FG status and dementia showed a U-shaped association.

CONCLUSION

Increased FG variability over 5 years can predict the risk of dementia in individuals with diabetes in Korea. This finding was more pronounced in patients with less favorable metabolic profiles.

Neurodynamic correlates for the cross-frequency coupled transcranial alternating current stimulation during working memory performance

Transcranial current stimulation is a neuromodulation technique used to modulate brain oscillations and, in turn, to enhance human cognitive function in a non-invasive manner. This study investigated whether cross-frequency coupled transcranial alternating current stimulation (CFC-tACS) improved working memory performance. Participants in both the tACS-treated and sham groups were instructed to perform a modified Sternberg task, where a combination of letters and digits was presented. Theta-phase/high-gamma-amplitude CFC-tACS was administered over electrode F3 and its four surrounding return electrodes (Fp1, Fz, F7, and C3) for 20 min. To identify neurophysiological correlates for the tACS-mediated enhancement of working memory performance, we analyzed EEG alpha and theta power, cross-frequency coupling, functional connectivity, and nodal efficiency during the retention period of the working memory task. We observed significantly reduced reaction times in the tACS-treated group, with suppressed treatment-mediated differences in frontal alpha power and unidirectional Fz-delta-phase to Oz-high-gamma-amplitude modulation during the second half of the retention period when network analyses revealed tACS-mediated fronto-occipital dissociative neurodynamics between alpha suppression and delta/theta enhancement. These findings indicate that tACS modulated top-down control and functional connectivity across the fronto-occipital regions, resulting in improved working memory performance. Our observations are indicative of the feasibility of enhancing cognitive performance by the CFC-formed tACS.

Night blood pressure variability, brain atrophy, and cognitive decline

Background

Although blood pressure variability (BPV) has emerged as a novel risk factor for Alzheimer's disease, few studies have examined the effects of night BPV on brain structure and function. This study investigated the association of night BPV with brain atrophy and cognitive function changes.

Methods

The analysis included 1,398 participants with valid ambulatory blood pressure (BP) monitoring at baseline and both baseline and 4-year follow-up brain magnetic resonance images who were recruited from the Korean Genome and Epidemiology Study. Participants underwent a comprehensive neuropsychological test battery. BPV was derived from ambulatory BP monitoring and calculated as a standard deviation (SD) of 24-h and daytime and nighttime BP.

Results

During the median follow-up of 4.3 years, increased SD of night systolic or diastolic BP was an indicator of total brain volume reduction, while daytime BPV or night average BP was not associated with total brain volume changes. High SD of night systolic BP was associated with reduced gray matter (GM) volume, independent of average night BP, and use of antihypertensive drugs. It also was associated with a reduction of temporal GM volume, mostly driven by atrophy in the left entorhinal cortex and the right fusiform gyrus. In cognitive performance, high variability of night systolic BP was associated with a decrease in visual delayed recall memory and verbal fluency for the category.

Conclusion

Increased night BPV, rather than night mean BP, was associated with reduced brain volume and cognitive decline. High night BPV could be an independent predictor for rapid brain aging in a middle-aged population.

Myocardial Infarction, Stroke, and All-Cause Mortality according to Low-Density Lipoprotein Cholesterol Level in the Elderly, a Nationwide Study

BACKGROUND

We assessed the myocardial infarction (MI), stroke, and all-cause death risks during follow-up according to the low-density lipoprotein cholesterol (LDL-C) levels among older adults.

METHODS

The Korean National Health Insurance Service datasets (2002 to 2020) were used for this population-based cohort study. The hazards of MI, stroke, and all-cause mortality during follow-up were analyzed according to LDL-C level in individuals aged ≥65 years without baseline cardiovascular diseases (n=1,391,616).

RESULTS

During a mean 7.55 years, 52,753 MIs developed; 84,224 strokes occurred over a mean 7.47 years. After a mean 8.50 years, 233,963 died. A decrease in LDL-C was associated with lower hazards of MI and stroke. The decreased hazard of stroke in lower LDL-C was more pronounced in statin users, and individuals with diabetes or obesity. The hazard of all-cause death during follow-up showed an inverted J-shaped pattern according to the LDL-C levels. However, the paradoxically increased hazard of mortality during follow-up in lower LDL-C was attenuated in statin users and individuals with diabetes, hypertension, or obesity. In statin users, lower LDL-C was associated with a decreased hazard of mortality during follow-up.

CONCLUSION

Among the elderly, lower LDL-C was associated with decreased risks of MI and stroke. Lower LDL-C achieved by statins in the elderly was associated with a decreased risk of all-cause death during follow-up, suggesting that LDL-C paradox for the premature death risk in the elderly should not be applied to statin users. Intensive statin therapy should not be hesitated for older adults with cardiovascular risk factors including diabetes.

The effect of sex and physical frailty on incident disability after 2 years among community-dwelling older adults: KFACS study

Background

This study investigated the impact of physical frailty on the development of disabilities in mobility, activities of daily living (ADL), and instrumental activities of daily living (IADL) according to sex among community-dwelling Korean older adults.

Methods

We used data of 2,905 older adults aged 70-84 years from the Korean Frailty and Aging Cohort Study (KFACS) at baseline (2016-2017) and Wave 2 (2018-2019). Fried’s physical frailty phenotype was used to identify frailty.

Results

After adjustment, frailty showed a higher impact for women than men on developing mobility disability (odds ratio [OR]=14.00, 95% confidence interval [CI]=4.8–40.78 vs. OR=9.89, 95% CI=4.28–22.86) and IADL disability after two years (OR=7.22, 95% CI=2.67–19.56 vs. OR=3.19, 95% CI=1.17–8.70). Pre-frailty led to mobility disability for women and men (OR=2.77, 95% CI=1.93–3.98 vs. OR=2.49, 95% CI=1.66–3.72, respectively), and IADL disability only for women (OR=3.01, 95% CI=1.28–7.09). Among the IADL components, both men and women who were prefrail or frail showed increased disability in ‘using transportation’. Among men, pre-frailty was significantly associated with disability in “going out” and “shopping”. In women, frailty was significantly associated with disability in “doing laundry,” “performing household chores,” “shopping,” and “managing money”.

Conclusions

Physical frailty increased disability over 2 years for women more than men. Physical frailty increased disability in outdoor activity-related IADL components in men and household work-related IADL components in women. This study highlights the need for gender-specific policies and preventative programs for frailty, particularly restorative interventions that focus on women who are physically frail.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03263-5.

Impact of non-alcoholic fatty liver disease on the risk of sarcopenia: a nationwide multicenter prospective study

BACKGROUND AND AIMS

Despite the association between sarcopenia and non-alcoholic fatty liver disease (NAFLD), no study has evaluated the predictive role of NAFLD in sarcopenia. We investigated impact of NAFLD on the risk of low muscle mass (LMM) and low muscle strength (LMS) in a nationwide multicenter study.

METHODS

A total of 1595 community-dwelling people aged 70-84 years were followed for 2 years in the Korean Frailty and Aging Cohort Study. Muscle mass was estimated by dividing appendicular skeletal muscle mass (ASM) by body mass index (BMI). Muscle strength was measured as handgrip strength (HGS) divided by BMI. The sex-specific lowest quintiles of ASM/BMI and HGS/BMI of the study population were used as cutoffs for LMM and LMS, respectively. The risk of LMM and LMS were assessed according to hepatic steatosis index (HSI) and fatty liver index (FLI) quartiles.

RESULTS

As HSI quartiles increased, the LMM risk increased gradually, after adjusting for age, sex, lifestyle factors, comorbidities, and several causative factors (insulin resistance, inflammation, and vitamin D) (Q4 vs. Q1 OR [95% CI] 3.46 [2.23-5.35]). The increased risk of LMS was even higher according to HSI quartiles (Q4 vs. Q1 5.81 [3.67-9.21]). Multivariate analyses based on FLI showed similar results. People with NAFLD (HSI > 36) were at higher risk of developing LMM and LMS compared to those without (1.65 [1.19-2.31] and 2.29 [1.61-3.26], respectively).

CONCLUSIONS

The presence of NAFLD may predict future risk of LMM and LMS, with greater impact on LMS than on LMM.

Sestrin2 Regulates Beneficial β3-Adrenergic Receptor-Mediated Effects Observed in Inguinal White Adipose Tissue and Soleus Muscle

Sestrin2, a well-known adenosine monophosphate-activated protein kinase (AMPK) regulator, plays a protective role against metabolic stress. The β3-adrenergic receptor (β3AR) induces fat browning and inhibits muscle atrophy in an AMPK-dependent manner. However, no prior research has examined the relationship of sestrin2 with β3AR in body composition changes. In this study, CL 316,243 (CL), a β3AR agonist, was administered to wild-type and sestrin2-knockout (KO) mice for 2 weeks, and fat and muscle tissues were harvested. CL induced AMPK phosphorylation, expression of brown-fat markers, and mitochondrial biogenesis, which resulted in the reduction of lipid droplet size in inguinal white adipose tissue (iWAT). These effects were not observed in sestrin2-KO mice. In CL-treated soleus muscle, sestrin2-KO was related to decreased myogenic gene expression and increased levels of muscle atrophy-related molecules. Our results suggest that sestrin2 is associated with beneficial β3AR-mediated changes in body composition, especially in iWAT and in the soleus.

Diabetes Fact Sheet in Korea 2021

BACKGROUND

This study aimed to investigate the prevalence and management of diabetes mellitus, risk-factor control, and comorbidities among Korean adults.

METHODS

We conducted a cross-sectional analysis of data from the Korea National Health and Nutrition Examination Survey to assess the prevalence, treatment, risk factors, comorbidities, and self-management behaviors of diabetes mellitus from 2019 to 2020. We also analyzed data from the Korean National Health Insurance Service to evaluate the use of antidiabetic medications in people with diabetes mellitus from 2002 through 2018.

RESULTS

Among Korean adults aged 30 years or older, the estimated prevalence of diabetes mellitus was 16.7% in 2020. From 2019 through 2020, 65.8% of adults with diabetes mellitus were aware of the disease and treated with antidiabetic medications. The percentage of adults with diabetes mellitus who achieved glycosylated hemoglobin (HbA1c) <6.5% was 24.5% despite the increased use of new antidiabetic medications. We found that adults with diabetes mellitus who achieved all three goals of HbA1c <6.5%, blood pressure (BP) <140/85 mm Hg, and low-density lipoprotein cholesterol <100 mg/dL were 9.7%. The percentage of self-management behaviors was lower in men than women. Excess energy intake was observed in 16.7% of adults with diabetes mellitus.

CONCLUSION

The prevalence of diabetes mellitus among Korean adults remained high. Only 9.7% of adults with diabetes mellitus achieved all glycemic, BP, and lipid controls from 2019 to 2020. Continuous evaluation of national diabetes statistics and a national effort to increase awareness of diabetes mellitus and improve comprehensive diabetes care are needed.

GPR40 Agonism Modulates Inflammatory Reactions in Vascular Endothelial Cells

Endothelial dysfunction is strongly linked with inflammatory responses, which can impact cardiovascular disease. Recently, G protein-coupled receptor 40 (GPR40) has been investigated as a modulator of metabolic stress; however, the function of GPR40 in vascular endothelial cells has not been reported. We analyzed whether treatment of GPR40-specific agonists modulated the inflammatory responses in human umbilical vein endothelial cells (HUVECs). Treatment with LY2922470, a GPR40 agonist, significantly reduced lipopolysaccharide (LPS)-mediated nuclear factor-kappa B (NF-κB) phosphorylation and movement into the nucleus from the cytosol. However, treatment with another GPR40 agonist, TAK875, did not inhibit LPS-induced NF-κB activation. LPS treatment induced expression of adhesion molecules vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and attachment of THP-1 cells to HUVECs, which were all decreased by LY2922470 but not TAK875. Our results showed that ligand-dependent agonism of GPR40 is a promising therapeutic target for overcoming inflammatory reactions in the endothelium.

Increased Risk of Type 2 Diabetes in Patients With Thyroid Cancer After Thyroidectomy: A Nationwide Cohort Study

CONTEXT

Abnormal thyroid function after thyroidectomy and subsequent thyroid-stimulating hormone suppression can have detrimental effects on glucose homeostasis in patients with thyroid cancer.

OBJECTIVE

To investigate whether thyroidectomy increases the risk of type 2 diabetes in patients with thyroid cancer and to explore the association between levothyroxine dosage and type 2 diabetes risk.

METHODS

A retrospective population-based cohort study using the Korean National Health Insurance database. We included 36 377 thyroid cancer patients without known diabetes who underwent thyroidectomy between 2004 and 2013. Matched subjects with nonthyroid cancer were selected using 1:1 propensity score matching. The main outcome measure was newly developed type 2 diabetes mellitus.

RESULTS

Patients with thyroid cancer who underwent thyroidectomy had a higher risk of developing type 2 diabetes mellitus than the matched controls (hazard ratio [HR] 1.43, 95% CI 1.39-1.47). Among patients with thyroid cancer, when the second quartile group (in terms of the mean levothyroxine dosage; 101-127 μg/day) was considered the reference group, the risk of type 2 diabetes mellitus increased in the first quartile (<101 μg/day; HR 1.45, 95% CI 1.36-1.54) and fourth quartile groups (≥150 μg/day; HR 1.37, 95% CI 1.29-1.45); meanwhile, the risk decreased in the third quartile group (128-149 μg/day; HR 0.91, 95% CI 0.85-0.97).

CONCLUSION

Patients with thyroid cancer who underwent thyroidectomy were more likely to develop type 2 diabetes mellitus than the matched controls. There was a U-shaped dose-dependent relationship between the levothyroxine dosage and type 2 diabetes mellitus risk.

Implications of fasting plasma glucose variability on the risk of incident peripheral artery disease in a population without diabetes: a nationwide population-based cohort study

Background

Diabetes have been known as a traditional risk factor of developing peripheral artery disease (PAD). However, the study evaluating the impact of long-term glycemic variability on the risk of developing PAD is limited, especially in a general population without diabetes.

Methods

We included 152,931 individuals without diabetes from the Korean National Health Insurance Service–Health Screening Cohort. Fasting plasma glucose (FPG) variability was measured using coefficient variance (FPG-CV), standard deviation (FPG-SD), and variability independent of the mean (FPG-VIM).

Results

A total of 16,863 (11.0%) incident cases of PAD were identified during a median follow-up of 8.3 years. Kaplan–Meier curves showed a progressively increasing risk of PAD in the higher quartile group of FPG variability than in the lowest quartile group (log rank P < 0.001). Multivariable Cox proportional hazard analysis showed the hazard ratio for PAD prevalence as 1.11 (95% CI 1.07–1.16, P < 0.001) in the highest FPG-CV quartile than in the lowest FPG-CV quartile after adjusting for confounding variables, including mean FPG. Similar degree of association was shown in the FPG-SD and FPG-VIM. In sensitivity analysis, the association between FPG variability and the risk of developing PAD persisted even after the participants were excluded based on previously diagnosed diseases, including stroke, coronary artery disease, congestive heart failure, chronic kidney disease, or current smokers or drinkers. Subgroup analysis demonstrated that the effects of FPG variability on the risk of PAD were more powerful in subgroups of younger age, regular exercisers, and those with higher income.

Conclusions

Increased long-term glycemic variability may have a significant prognostic effect for incident PAD in individuals without diabetes.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01448-1.

Association between Variability of Metabolic Risk Factors and Cardiometabolic Outcomes

Despite strenuous efforts to reduce cardiovascular disease (CVD) risk by improving cardiometabolic risk factors, such as glucose and cholesterol levels, and blood pressure, there is still residual risk even in patients reaching treatment targets. Recently, researchers have begun to focus on the variability of metabolic variables to remove residual risks. Several clinical trials and cohort studies have reported a relationship between the variability of metabolic parameters and CVDs. Herein, we review the literature regarding the effect of metabolic factor variability and CVD risk, and describe possible mechanisms and potential treatment perspectives for reducing cardiometabolic risk factor variability.

Fasting Glucose Variability as a Risk Indicator for End-Stage Kidney Disease in Patients with Diabetes: A Nationwide Population-Based Study

Given the fact that diabetes remains a leading cause of end-stage kidney disease (ESKD), multi-aspect approaches anticipating the risk for ESKD and timely correction are crucial. We investigated whether fasting glucose variability (FGV) could anticipate the development of ESKD and identify the population prone to the harmful effects of GV. We included 777,192 Koreans with diabetes who had undergone health examinations more than three times in 2005-2010. We evaluated the risk of the first diagnosis of ESKD until 2017, according to the quartile of variability independent of the mean (VIM) of FG using multivariate-adjusted Cox proportional hazards analyses. During the 8-year follow-up, a total of 7290 incidents of ESKD were found. Subjects in the FG VIM quartile 4 had a 27% higher risk for ESKD compared to quartile 1, with adjustment for cardiovascular risk factors and the characteristics of diabetes. This effect was more distinct in patients aged < 65 years; those with a long duration of diabetes; the presence of hypertension or dyslipidemia; and prescribed angiotensin-converting enzyme inhibitors, metformin, sulfonylurea, α-glucosidase inhibitors, and insulin. In contrast, the relationship between baseline FG status and ESKD risk showed a U-shaped association. FGV is an independent risk factor for kidney failure regardless of FG.

Risk of Diabetes in Patients with Long-Standing Graves' Disease: A Longitudinal Study

BACKGROUND

The detrimental effects of excessive thyroid hormone on glucose metabolism have been widely investigated. However, the risk of diabetes in patients with long-standing hyperthyroidism, especially according to treatment modality, remains uncertain, with few longitudinal studies.

METHODS

The risk of diabetes in patients with Graves' disease treated with antithyroid drugs (ATDs) for longer than the conventional duration (≥2 years) was compared with that in age-and sex-matched controls. The risk was further compared according to subsequent treatment modalities after a 24-month course of ATD: continuation of ATD (ATD group) vs. radioactive iodine ablation (RIA) group.

RESULTS

A total of 4,593 patients were included. Diabetes was diagnosed in 751 (16.3%) patients over a follow-up of 7.3 years. The hazard ratio (HR) for diabetes, after adjusting for various known risk factors, was 1.18 (95% confidence interval [CI], 1.10 to 1.28) in patients with hyperthyroidism. Among the treatment modality groups, the RIA group (n=102) had a higher risk of diabetes than the ATD group (n=4,491) with HR of 1.56 (95% CI, 1.01 to 2.42). Further, the risk of diabetes increased with an increase in the ATD treatment duration (P for trend=0.019).

CONCLUSION

The risk of diabetes was significantly higher in patients with long-standing Graves' disease than in the general population, especially in patients who underwent RIA and prolonged ATD treatment. Special attention to hyperglycemia during follow-up along with effective control of hyperthyroidism may be necessary to reduce the risk of diabetes in these patients.

Implication of thyroid function in periodontitis: a nationwide population-based study

Possible links between periodontitis and various cardiometabolic and autoimmune diseases have been advocated on the basis of chronic inflammation or oxidative stress. However, the association between periodontitis and thyroid dysfunction is under-researched. Participants without previous thyroid disease or ongoing thyroid-related medication were included from a nationwide population-level survey. Participants were categorized into tertiles of thyroid stimulating hormone (TSH) levels (first tertile < 1.76 mIU/L; second tertile 1.76-2.83 mIU/L; third tertile > 2.83 mIU/L), and periodontal condition was assessed using the Community Periodontal Index. Of the total of 5468 participants, 1423 had periodontitis (26%). A significant difference in the weighted prevalence of periodontitis according to TSH tertiles was observed, with the highest prevalence in the first tertile (26.5%) and the lowest prevalence in the third tertile (20.9%, p = 0.003). Subjects in the first TSH tertile had higher odds for periodontitis than those in the third tertile (OR 1.36, 95% CI 1.10-1.68; p for trend = 0.005) after adjusting for covariates. This association was consistent across subgroups and within sensitivity analyses among subjects without specific factors affecting thyroid function or diseases reported to be related to periodontitis. The present study demonstrated that low TSH levels were associated with significantly higher odds for periodontitis.

Association of plasma FGF21 levels with muscle mass and muscle strength in a national multicentre cohort study: Korean Frailty and Aging Cohort Study

BACKGROUND

despite of the beneficial effects of fibroblast growth factor (FGF) 21 in several metabolic diseases, the association of plasma FGF21 with muscle mass and muscle strength is still unclear.

METHODS

a total of 386 community-dwelling older adults aged 70-84 years were analysed. Appendicular skeletal muscle mass was measured using dual-energy X-ray absorptiometry and normalised to the square of height (ASM/ht2). Muscle strength was assessed using the hand grip strength (HGS) test. The definitions of low muscle mass (LMM) and low muscle strength (LMS) were based on the Asian Working Group for Sarcopenia.

RESULTS

plasma FGF21 was significantly lower in participants with LMM than in those with normal muscle mass (289.7 [192.4-448.3] vs. 345.6 [238.6-503.2] pg/ml, P = 0.008). In contrast, the LMS group had a significantly higher plasma FGF21 level than the normal muscle strength group (369.7 [244.4-591.1] vs. 309.7 [205.3-444.8] pg/ml, P = 0.006). In the partial correlation analysis, following adjustment for age, sex and body mass index, FGF21 levels had no significant association with ASM/ht2, but were negatively associated with HGS (r = -0.112, P = 0.029). Furthermore, after multivariate adjustment for confounding variables, the odds ratio for the risk of LMS was 2.32 (95% confidence interval 1.20-4.46) when comparing the highest with the lowest FGF21 quartile.

CONCLUSIONS

circulating FGF21 levels are negatively associated with muscle strength but are not independently correlated with muscle mass.

Sarcopenia is associated with decreased gray matter volume in the parietal lobe: a longitudinal cohort study

Background

Substantial evidence supports an association between physical activity and cognitive function. However, the role of muscle mass and function in brain structural changes is not well known. This study investigated whether sarcopenia, defined as low muscle mass and strength, accelerates brain volume atrophy.

Methods

A total of 1284 participants with sarcopenic measurements and baseline and 4-year follow-up brain magnetic resonance images were recruited from the Korean Genome and Epidemiology Study. Muscle mass was represented as appendicular skeletal muscle mass divided by the body mass index. Muscle function was measured by handgrip strength. The low mass and strength groups were defined as being in the lowest quintile of each variable for one’s sex. Sarcopenia was defined as being in the lowest quintile for both muscle mass and handgrip strength.

Results

Of the 1284 participants, 12·6%, 10·8%, and 5·4% were classified as the low mass, low strength, and sarcopenia groups, respectively. The adjusted mean changes of gray matter (GM) volume during 4-year follow-up period were − 9·6 mL in the control group, whereas − 11·6 mL in the other three groups (P < 0·001). The significantly greater atrophy in parietal GM was observed in the sarcopenia group compared with the control group. In a joint regression model, low muscle mass, but not muscle strength, was an independent factor associated with a decrease of GM volume.

Conclusions

Sarcopenia is associated with parietal GM volume atrophy, in a middle-aged population. Maintaining good levels of muscle mass could be important for brain health in later adulthood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02581-4.

Combination of Statin and Ezetimibe versus Statin Monotherapy on Cardiovascular Disease and Type 2 Diabetes Incidence among Adults with Impaired Fasting Glucose: a Propensity-Matched Nationwide Cohort Study

Objective

We investigated the effects of statin-ezetimibe combination therapy compared with statin-only treatment on the hazard of incident type 2 diabetes (T2D), myocardial infarction (MI), and stroke among adults with impaired fasting glucose (IFG) in a real-world setting.

Methods

The Korean National Health Insurance Service datasets from 2002 to 2017 were used for this propensity-matched nationwide cohort study. Among 56,633 IFG patients without baseline cardiovascular disease (CVD) and/or T2D who initiated statin therapy with or without ezetimibe, 1,155 with statin-ezetimibe combination therapy were matched based on a propensity score at a 1:5 ratio with 5,775 patients who received statin monotherapy. The hazards of T2D, MI, and stroke were compared between these treatment groups.

Results

The incidence rate per 1,000 person-years was 19.62 (statin monotherapy group) and 21.02 (combined treatment group) for T2D, 1.53 (statin monotherapy group) and 1.70 (combined treatment group) for MI, and 1.99 (statin monotherapy group) and 2.06 (combined treatment group) for stroke. The hazards of T2D, MI, and stroke were not significantly different between the statin monotherapy group and the statin-ezetimibe combination therapy group.

Conclusion

The combination of ezetimibe in addition to statin treatment was not associated with a significantly different risk of T2D and CVDs compared with statin monotherapy in Korean adults with IFG.

Statin Therapy and the Risk of Osteoporotic Fractures in Patients with Metabolic Syndrome: a Nested Case-Control Study

OBJECTIVE

We aimed to investigate the association between statin use and the risk of major osteoporotic fractures in patients with metabolic syndrome (MetS).

METHODS

A nested case-control study was performed in patients with MetS (≥50 years) who had no history of osteoporotic fracture using the Korean National Health Insurance Service-Health Screening Cohort. This study included 17,041 patients diagnosed with new-onset osteoporotic fractures and controls matched in a 1:1 ratio by age, sex, body mass index, cohort entry date, and follow-up duration. Conditional logistic regression analysis was used to evaluate covariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

During a 4-year follow-up period, the risk of major osteoporotic fractures was significantly reduced by 9% (OR, 0.91; 95% CI, 0.85-0.97) in statin users compared with that in non-users. Among subtypes of major osteoporotic fracture, a risk reduction with statin therapy was significant for vertebral fracture (OR, 0.86; 95% CI, 0.79-0.94) but not for non-vertebral fracture (OR, 0.97; 95% CI, 0.88-1.06). Longer duration (OR, 0.97; 95% CI, 0.96-0.99, per 1-year increase) and higher cumulative dose (OR, 0.97; 95% CI, 0.95-0.99, per 365 defined daily doses) of statins were negatively associated with the risk of major osteoporotic fracture.

CONCLUSION

This study supports the hypothesis that statin therapy has a beneficial effect on major osteoporotic fractures, especially vertebral fractures, in patients with MetS.

Association Between Visit-to-Visit Fasting Plasma Glucose Variability and Osteoporotic Fractures in Nondiabetic Subjects

CONTEXT

Although long-term glucose variability has been reported to be a risk factor associated with osteoporosis, there have been no previous studies between the relationship of glucose variability and fractures in people without diabetes.

OBJECTIVE

We assessed visit-to-visit variations in fasting plasma glucose (FPG) as a prognostic factor in predicting osteoporotic fractures in individuals without diabetes.

METHODS

Using a nationwide cohort database, we examined the impact of FPG on the development of osteoporotic fractures in men and women (aged ≥50 years). The primary outcomes were the number of total fractures and vertebral fractures. FPG variability was measured using standard deviation (FPG-SD), coefficient of variation (FPG-CV), and variability independent of the mean (FPG-VIM).

RESULTS

Of the 92 929 participants, 5262 (5.7%) developed osteoporotic fractures during the mean follow-up of 8.4 years. Individuals in the highest quartile of FPG-SD showed an 11% and 16% increase in risk of total and vertebral fractures, respectively, compared with those in the lowest quartile after adjustment for mean FPG and other risk factors. Analyses using FPG-CV and FPG-VIM demonstrated similar results. Subgroup analyses and sensitivity analyses to explore potential heterogeneity showed consistent results.

CONCLUSION

FPG variability may be a novel risk factor for osteoporotic fractures independent of risk factors in the general population without diabetes.

Glycemic variability and the risk of nonalcoholic fatty liver disease : A nationwide population-based cohort study

AIM

Although few recent studies have reported the association between the glycemic variability and the development of type 2 diabetes mellitus and cardiovascular disease in individuals without diabetes mellitus, the impact of the long-term variability in fasting plasma glucose (FPG) levels on the incident nonalcoholic fatty liver disease (NAFLD) has not been evaluated.

METHODS

The study included 57,636 Korean men and women without NAFLD and diabetes mellitus from the Korean National Health Insurance System cohort. FPG variability was calculated using the coefficient of variation (FPG-CV), standard deviation (FPG-SD), variability independent of the mean (FPG-VIM), and average successive variability (FPG-ASV).

RESULTS

The cumulative incidence of NAFLD demonstrated progressively increasing trends according to the higher quartiles of FPG variability in Kaplan-Meier curves. A multivariable Cox proportional hazard analysis revealed that the hazard ratio for incident NAFLD was 1.15 (95% confidence interval, 1.06-1.24) in the highest quartile of FPG-CV compared with the lowest quartile of FPG-CV after adjusting for various confounding factors, including mean FPG levels. When using FPG-SD, FPG-VIM, and FPG-ASV, the results were similar. The 10-unit increase in FPG variability was associated with a 14% increased risk of NAFLD in the fully adjusted model. Moreover, this effect remained consistent in the subgroup and sensitivity analyses.

CONCLUSION

Increased long-term FPG variability is associated with the development of NAFLD, independent of confounding risk variables including mean FPG levels.

Effect of Statin Use on the Risk of Osteoporotic Fracture in Patients With Metabolic Syndrome: A Nested Case-Control Study

Statins may have advantageous pleiotropic effects on bone metabolism, however, the clinical evidence about the association is still unclear. Although many studies have already evaluated this association, they have performed mostly in a general population with limitation of between-study heterogeneity. Statin may not be equally effective for bone metabolism to every patient, but it can give some benefits for some patients especially with metabolic syndrome (MetS). However, no recent study assessing this relationship, to best our knowledge, has evaluated specifically on patients with MetS. It is also unclear whether the association between statin and osteoporotic fracture differ by statin intensity, dose (cumulative defined daily dose), and duration. This study aimed to investigate the association of statin use with the risk of major osteoporotic fracture in MetS patients from a population-based cohort (NHIS-HEALS, 2002–2015). A nested case-control study was performed in patients with MetS (≥50 years) who had no history of previous osteoporotic fracture. This study included 17,041 cases diagnosed as new-onset osteoporotic fractures and controls matched in a 1:1 ratio by age, sex, body mass index, cohort entry date, and follow-up duration. Conditional logistic regression analysis was used to evaluate covariate-adjusted odds ratio (OR) and 95% confidence interval (CI). During the 4-year follow up period, statin users had a significantly lower risk of major osteoporotic fractures by 9% (OR, 0.91; 95% CI, 0.85 to 0.97) compared with non-users. Among subtypes of major osteoporotic fracture, a risk reduction of vertebral fracture was significant (OR, 0.86; 95% CI, 0.79 to 0.94), but not non-vertebral fracture (OR, 0.97; 95% CI, 0.88 to 1.06) with statin use. Longer duration (OR, 0.97 per 1 year) and cumulative dose (OR, 0.97 per 365 defined daily dose) of statin was negatively associated with the risk of major osteoporotic fracture. There was no difference in risk of major osteoporotic fractures among groups according to statin intensity. In conclusion, this study supports the hypothesis that statin treatment has a beneficial effect on major osteoporotic fracture, especially for vertebral fracture, in patients with MetS with a possibly dose-effect relationship.

Time to Reach Target Glycosylated Hemoglobin Is Associated with Long-Term Durable Glycemic Control and Risk of Diabetic Complications in Patients with Newly Diagnosed Type 2 Diabetes Mellitus: A 6-Year Observational Study

BACKGROUND

To evaluate the association of time to reach the target glycosylated hemoglobin (HbA1c) level with long-term durable glycemic control and risk of diabetic complications in patients with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

In a longitudinal observational cohort, 194 patients with T2DM newly diagnosed between January 2011 and March 2013 were followed up over 6 years. Patients were classified according to the time needed to reach the target HbA1c (<7.0%): <3, 3 to 6 (early achievement group), and ≥6 months (late achievement group). Risks of microvascular complications including diabetic retinopathy, nephropathy, and neuropathy as well as macrovascular events including ischemic heart disease, ischemic stroke, and peripheral arterial disease were assessed by multivariable Cox proportional hazards analysis.

RESULTS

During a median follow-up of 6.53 years, 66 microvascular and 14 macrovascular events occurred. Maintenance of durable glycemic control over 6 years was more likely in the early achievement groups than in the late achievement group (34.5%, 30.0%, and 16.1% in <3, 3 to 6, and ≥6 months, respectively, P=0.039). Early target HbA1c achievement was associated with lower risk of composite diabetic complications (adjusted hazard ratio [HR, 0.47; 95% confidence interval [CI], 0.26 to 0.86 in <3 months group) (adjusted HR, 0.50; 95% CI, 0.23 to 1.10 in 3 to 6 months group, in reference to ≥6 months group). Similar trends were maintained for risks of microvascular and macrovascular complications, although statistical significance was not reached for macrovascular complications.

CONCLUSION

Early target HbA1c achievement was associated with long-term durable glycemic control and reduced risk of diabetic complications in newly diagnosed T2DM.

Age- and Sex-Related Differential Associations between Body Composition and Diabetes Mellitus

BACKGROUND

The age- and sex-related differences on the impacts of body composition on diabetes mellitus (DM) remain uncertain.

METHODS

The fourth and fifth Korea National Health and Nutrition Examination Survey included 15,586 subjects over 30 years of age who completed dual-energy X-ray absorptiometry. We conducted a cross-sectional study to investigate whether muscle mass index (MMI), defined as appendicular skeletal muscle divided by body mass index (BMI), and fat mass index (FMI), defined as trunk fat mass divided by BMI, were differently associated with DM according to age and sex.

RESULTS

In multivariate logistic regression, the risk for DM significantly increased across quartiles of FMI in men aged ≥70. Meanwhile, MMI showed a protective association with DM in men of the same age. The odds ratios (ORs) for the highest quartile versus the lowest quartile of FMI and MMI were 3.116 (95% confidence interval [CI], 1.405 to 6.914) and 0.295 (95% CI, 0.157 to 0.554), respectively. In women, the ORs of DM was significantly different across FMI quartiles in those over age 50. The highest quartile of FMI exhibited increased ORs of DM in subjects aged 50 to 69 (OR, 1.891; 95% CI, 1.229 to 2.908) and ≥70 (OR, 2.275; 95% CI, 1.103 to 4.69) compared to lowest quartile. However, MMI was not significantly associated with DM in women of all age groups.

CONCLUSION

Both FMI and MMI were independent risk factors for DM in men aged 70 years or more. In women over 50 years, FMI was independently associated with DM. There was no significant association between MMI and DM in women.

Association between living alone and incident type 2 diabetes among middle-aged individuals in Korea: a nationwide cohort study

We studied the association between living alone and the risk of incident type 2 diabetes in middle-aged individuals using nationwide cohort data from the Korean population. 11,686, 677 middle-aged individuals aged 40–64 years who underwent health examinations by the Korean National Health Insurance System between 2009 and 2012 were followed up until December 31, 2015. The hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards regression analysis. During the median follow-up duration of 5.6 years, 393,438 individuals developed type 2 diabetes. Living alone was significantly associated with incident type 2 diabetes in all adjusted models (HR 1.08; 95% CI 1.07–1.09 in model 4). Individuals who lived alone for < 1 year and 1–7 years were associated with increased HRs of 1.07 (1.04–1.09) and 1.08 (1.07–1.09). Living alone was associated with incident type 2 diabetes in all subgroups. The association was stronger in men than in women and younger individuals than in older individuals. Living alone, even for a short duration, may be an important factor in type 2 diabetes development. Better household conditions and appropriate support to one-person households may be needed to prevent type 2 diabetes.

Optimal blood pressure for patients with chronic kidney disease: a nationwide population-based cohort study

The effect of blood pressure (BP) on the incident cardiovascular events, progression to end-stage renal disease (ESRD) and mortality were evaluated among chronic kidney disease (CKD) patients with and without antihypertensive treatment. This nationwide study used the Korean National Health Insurance Service-Health Screening Cohort data. The hazards of outcomes were analysed according to the systolic BP (SBP) or diastolic BP (DBP) among adults (aged ≥ 40 years) with CKD and without previous cardiovascular disease or ESRD (n = 22,278). The SBP and DBP were ≥ 130 mmHg and ≥ 80 mmHg in 10,809 (48.52%) and 11,583 (51.99%) participants, respectively. During a median 6.2 years, 1271 cardiovascular events, 201 ESRD incidents, and 1061 deaths were noted. Individuals with SBP ≥ 130 mmHg and DBP ≥ 80 mmHg had higher hazards of hypertension-related adverse outcomes compared to the references (SBP 120-129 mmHg and DBP 70-79 mmHg). SBP < 100 mmHg was associated with hazards of all-cause death, and composite of ESRD and all-cause death during follow-up only among the antihypertensive medication users suggesting that the BP should be < 130/80 mmHg and the SBP should not be < 100 mmHg with antihypertensive agents to prevent the adverse outcome risk of insufficient and excessive antihypertensive treatment in CKD patients.

Association of the triglyceride and glucose index with low muscle mass: KNHANES 2008-2011

The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance. We evaluated the association of the TyG index with low muscle mass using a nationwide population-based representative data. This is a cross-sectional study that included 9477 participants aged ≥ 40 years from the Korea National Health and Nutrition Examination Survey between 2008 and 2011. The TyG index was calculated as ln[triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2]. Dual-energy X-ray absorptiometry was used to measure appendicular lean mass (ALM). Low muscle mass was defined an ALM/weight of 2 standard deviations (SD) below of young participants. The overall prevalence of low muscle mass was 4.7%. The prevalence of low muscle mass increased linearly with the quartiles of the TyG index, 2.5%, 4.2%, 5.6%, and 6.7% in Q1–Q4, respectively. The TyG index was negatively associated with ALM/weight both in men (r = − 0.302) and women (r = − 0.230). The odds ratio (OR) for low muscle mass was 2.08 in the highest quartile compared to the lowest quartile. High TyG index was associated with an increased risk of low muscle mass (OR for 1SD increase: 1.13). Increased TyG index was associated with the risk of low muscle mass independent of confounding factors.

Long Working Hours and Risk of Nonalcoholic Fatty Liver Disease: Korea National Health and Nutrition Examination Survey VII

BACKGROUND

The global incidence of NAFLD is rising sharply due to various risk factors. As previous studies reported adverse health impact of long working hours on metabolic diseases, such as diabetes mellitus and obesity, it is plausible that NAFLD is also associated with working excessive hours. However, data regarding this issue is limited.

METHODS

In this cross-sectional study based on Korea National Health and Nutrition Examination Survey VII, 5,661 working adults without previous liver disease or heavy alcohol drinking habits were included. The subjects were categorized into three groups according to working hours: 36-42, 43-52, and 53-83 hours/week. NAFLD was defined using the hepatic steatosis index (HSI), which is a validated prediction model for determining NAFLD.

RESULTS

The prevalence of NAFLD (HSI ≥36) increased with longer working hours: 23.0%, 25.6%, and 30.6% in the 36-42, 43-52, and 53-83 hours/week group, respectively (p <0.001). Subjects who worked 53-83 hours/week had higher odds for NAFLD than those who worked the standard 36-42 hours/week (OR 1.23, 95% CI 1.02-1.50, p = 0.033) after adjusting for age, sex, body mass index, smoking, alcohol, exercise, diabetes mellitus, hypertension, serum triglyceride, and total cholesterol. This association was consistent across subgroups according to working schedule (daytime vs. shift workers) or occupation type (office vs. manual workers). In particular, the relationship between long working hours and NAFLD was pronounced in workers aged <60 years and in female workers.

CONCLUSIONS

Long working hours was significantly associated with NAFLD. Further prospective studies are required to validate this finding with causal relationship.