Global, regional, and national burden of type 1 diabetes in adolescents and young adults.

BACKGROUND: Type 1 diabetes (T1D) incidence in adolescents varies widely, but has increased globally in recent years. This study reports T1D burden among adolescents and young adults aged 10-24-year-old age group at global, regional, and national levels. METHODS: Based on the Global Burden of Disease Study 2019, we described the burden of T1D in the 10-24-year-old age group. We further analyzed these trends by age, sex, and the Social Development Index. Joinpoint regression analysis was used to assess temporal trends. RESULTS: T1D incidence among adolescents and young adults increased from 7·78 per 100,000 population (95% UI, 5·27-10·60) in 1990 to 11·07 per 100,000 population (95% UI, 7·42-15·34) in 2019. T1D mortality increased from 5701·19 (95% UI, 4642·70-6444·08) in 1990 to 6,123·04 (95% UI, 5321·82-6887·08) in 2019, representing a 7·40% increase in mortality. The European region had the highest T1D incidence in 2019. Middle-SDI countries exhibited the largest increase in T1D incidence between 1990 and 2019. CONCLUSION: T1D is a growing health concern globally, and T1D burden more heavily affects countries with low SDI. Specific measures and effective collaboration among countries with different SDIs are required to improve diabetes care in adolescents. IMPACT: We assessed trends in T1D incidence and burden among youth in the 10-24-year-old age group by evaluating data from the Global Burden of Disease Study 2019. Our results demonstrated that global T1D incidence in this age group increased over the past 30 years, with the European region having the highest T1D incidence. Specific measures and effective collaboration among countries with different SDIs are required to improve diabetes care in adolescents.

Effects of altitude on thyroid disorders according to Chinese three-rung, ladder-like topography: national cross-sectional study.

BACKGROUND: Chinese topography appears a three-rung ladder-like distribution of decreasing elevation from northwest to southeast, which is divided by two sloping edges. Previous studies have reported that prevalence of thyroid diseases differed by altitude, and geographical factors were associated with thyroid disorders. To explore the association between three-rung ladder-like regions and thyroid disorders according to unique Chinese topographic features, we conducted an epidemiological cross-sectional study from 2015-2017 that covered all 31 mainland Chinese provinces. METHODS: A total of 78,470 participants aged ≥ 18 years from a nationally representative cross-sectional study were included. Serum thyroid peroxidase antibody, thyroglobulin antibody, and thyroid-stimulating hormone levels; urine iodine concentration; and thyroid volume were measured. The three-rung ladder-like distribution of decreasing elevation from northwest to southeast in China was categorized into three topographic groups according to elevation: first ladder, > 3000 m above sea level; second ladder, descending from 3000-500 m; and third ladder, descending from 500 m to sea level. The third ladder was further divided into groups A (500-100 m) and B (< 100 m). Associations between geographic factors and thyroid disorders were assessed using linear and binary logistic regression analyses. RESULTS: Participants in the first ladder group were associated with lower thyroid peroxidase (ß = -4.69; P = 0.00), thyroglobulin antibody levels (ß = -11.08; P = 0.01), and the largest thyroid volume (ß = 1.74; P = 0.00), compared with the other groups. The second ladder group was associated with autoimmune thyroiditis (odds ratio = 1.30, 95% confidence interval [1.18-1.43]) and subclinical hypothyroidism (odds ratio = 0.61, 95%confidence interval [0.57-0.66]) (P < 0.05) compared with the first ladder group. Group A (third ladder) (500-100 m) was associated with thyroid nodules and subclinical hypothyroidism (P < 0.05). Furthermore, group B (< 100 m) was positively associated with autoimmune thyroiditis, thyroid peroxidase and thyroglobulin antibody positivity, and negatively associated with overt hypothyroidism, subclinical hypothyroidism, and goiter compared with the first ladder group(P < 0.05). CONCLUSION: We are the first to investigate the association between different ladder regions and thyroid disorders according to unique Chinese topographic features. The prevalence of thyroid disorders varied among the three-rung ladder-like topography groups in China, with the exception of overt hyperthyroidism.

Effect of Levothyroxine Supplementation on the Cardiac Morphology and Function in Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis.

CONTEXT: The impact of abnormal thyroid hormone levels on the cardiovascular system has been explored for decades. Recent emerging evidence suggests that subclinical thyroid dysfunction, especially subclinical hypothyroidism (SCH), significantly affects cardiac indices. OBJECTIVE: We aimed to determine whether levothyroxine (LT4), commonly used to treat hypothyroidism, affects cardiovascular indices in SCH patients. METHODS: This is a systematic review and meta-analysis. We searched online databases for studies analyzing cardiac morphology and functional changes in SCH patients before and after LT4 supplementation. A total of 294 SCH patients participated and finished the follow-up. The standard mean difference and 95% CI were calculated in fixed or random-effects models. The clinical outcomes analyzed in this study included 18 indicators, mainly covering cardiac morphology, myocardial performance (including various indicators of systolic and diastolic function), mitral wave flow, and systemic vascular resistance. RESULTS: A total of 11 studies met our search criteria. All studies explicitly mentioned that serum thyrotropin levels decreased to normal at follow-up. Our results suggest that the cardiac output (CO), left ventricular ejection fraction (LVEF), and the ratio of peak E velocity/peak A velocity were all significantly increased after LT4 supplementation compared with the baseline level. However, we found no clear evidence of significant morphological changes in the heart. CONCLUSION: Judging from the obvious changes in the CO, LVEF, and E/A ratio, LT4 supplementation can effectively improve the cardiac systolic and diastolic dysfunction prevalent in SCH patients. This study provides evidence of the recommendation for LT4 supplementation in adult SCH patients.