Atypical juvenile hereditary hemochromatosis onset with positive pancreatic islet autoantibodies diabetes caused by novel mutations in HAMP and overall clinical management.

BACKGROUND: Atypical clinical symptoms of juvenile hereditary hemochromatosis (JHH) often leads to misdiagnosis and underdiagnosis bringing ominous outcomes, even death. METHODS: The whole exome was sequenced and interpreted. A literature review assisted to analyze and verify the phenotype-genotype relationships. We revealed the entire process of diagnosis, treatments, and outcome of two diabetic onset of JHH families to provide new insights for genotype-phenotype relation with novel compound heterozygous mutations in the hepcidin antimicrobial peptide (HAMP, OMIM: 606464). RESULTS: Two probands were diagnosed and treated as type 1 diabetes initially because of specific symptoms and positive islet autoantibodies. Poor control of hyperglycemia and progressive symptoms occurred. Sequencing informed that the compound heterozygous and homozygous mutations c.166C>G and c.223C>T in HAMP caused type 1 diabetic-onset JHH. The two patients accessed irregular phlebotomy treatments, and then, experienced poor prognosis. We summarized the process of overall clinical management of reported 26 cases comparing to our novel atypical diabetic onsets Juvenile Hereditary Hemochromatosis cases. CONCLUSION: It was first reported that positive pancreatic islet autoantibodies diabetes onset of JHH resulted from loss-of-function mutations of HAMP, of which the atypical JHH should be differentially diagnosed with type 1 diabetes at the onset. Early administration of phlebotomy and vital organs protection and surveillance might be important for the treatment of atypical JHH.

Association between bile acid metabolism and bone mineral density in postmenopausal women.

OBJECTIVES: Previous studies have not shown any correlation between bile acid metabolism and bone mineral density (BMD) in women with postmenopausal osteoporosis. Thus, the current study evaluated the association between bile acid levels as well as BMD and bone turnover marker levels in this group of women. METHODS: This single-center cross-sectional study included 150 postmenopausal Chinese women. According to BMD, the participants were divided into three groups: osteoporosis group, osteopenia group, and healthy control group. Serum bile acid, fibroblast growth factor 19 (FGF19), and bone turnover biomarker levels were assessed. Moreover, the concentrations of parathyroid hormone, 25-hydroxy vitamin D [25(OH)D], procollagen type I N-peptide (P1NP), and beta-CrossLaps of type I collagen containing cross-linked C-terminal telopeptide (ß-CTX) were evaluated. The BMD of the lumbar spine and proximal femur were examined via dual-energy X-ray absorptiometry. RESULTS: The serum total bile acid levels in the osteoporosis and osteopenia groups (5.28±1.56 and 5.31±1.56 umol/L, respectively) were significantly lower than that in the healthy control group (6.33±2.04 umol/L; p=0.002 and 0.018, respectively). Serum bile acid level was positively associated with the BMD of the lumbar spine, femoral neck, and total hip. However, it negatively correlated with ß-CTX concentration. Moreover, no correlation was observed between bile acid and P1NP levels, and the levels of the other biomarkers that were measured did not differ between the groups. CONCLUSION: Serum bile acid was positively correlated with BMD and negatively correlated with bone turnover biomarkers reflecting bone absorption in postmenopausal women. Thus, bile acid may play an important role in bone metabolism.

Association between bile acid metabolism and bone mineral density in postmenopausal women

OBJECTIVES: Previous studies have not shown any correlation between bile acid metabolism and bone mineral density (BMD) in women with postmenopausal osteoporosis. Thus, the current study evaluated the association between bile acid levels as well as BMD and bone turnover marker levels in this group of women. METHODS: This single-center cross-sectional study included 150 postmenopausal Chinese women. According to BMD, the participants were divided into three groups: osteoporosis group, osteopenia group, and healthy control group. Serum bile acid, fibroblast growth factor 19 (FGF19), and bone turnover biomarker levels were assessed. Moreover, the concentrations of parathyroid hormone, 25-hydroxy vitamin D [25(OH)D], procollagen type I N-peptide (P1NP), and beta-CrossLaps of type I collagen containing cross-linked C-terminal telopeptide (β-CTX) were evaluated. The BMD of the lumbar spine and proximal femur were examined via dual-energy X-ray absorptiometry. RESULTS: The serum total bile acid levels in the osteoporosis and osteopenia groups (5.28±1.56 and 5.31±1.56 umol/L, respectively) were significantly lower than that in the healthy control group (6.33±2.04 umol/L; p=0.002 and 0.018, respectively). Serum bile acid level was positively associated with the BMD of the lumbar spine, femoral neck, and total hip. However, it negatively correlated with β-CTX concentration. Moreover, no correlation was observed between bile acid and P1NP levels, and the levels of the other biomarkers that were measured did not differ between the groups. CONCLUSION: Serum bile acid was positively correlated with BMD and negatively correlated with bone turnover biomarkers reflecting bone absorption in postmenopausal women. Thus, bile acid may play an important role in bone metabolism.

Urinary methylmalonic acid as an indicator of early vitamin B12 deficiency and its role in polyneuropathy in type 2 diabetes.

The rising incidence of diabetes and its negative impact on quality of life highlights the urgent need to develop biomarkers of early nerve damage. Measurement of total vitamin B12 has some limitations. We want to determine the levels of urinary methylmalonic acid and its relationships with serum vitamin B12 and polyneuropathy. The 176 Chinese patients with Type 2 diabetes mellitus were divided into 3 groups according to the levels of vitamin B12. A gas chromatography mass spectrometric technique was used to determine blood methylmalonic acid and urinary methylmalonic acid. The diagnosis of distal diabetic polyneuropathy was based on the determination of bilateral limb sensory and motor nerve conduction velocity and amplitude with electromyogram. Multiple regression analysis revealed that urinary methylmalonic acid/creatinine, blood methylmalonic acid, and so forth were variables that influenced diabetic polyneuropathy significantly. Nerve sensory conduction velocity and nerve amplitude in the group of urinary methylmalonic acid/creatinine >3.5 mmol/mol decreased significantly. Superficial peroneal nerve sensory and motor conduction velocity and ulnar nerve compound motor active potential amplitude were inversely correlated with urinary methylmalonic acid/creatinine. Urinary methylmalonic acid correlates with serum vitamin B12 levels in person with diabetes and is a sensitive marker of early polyneuropathy.

Dipeptidyl peptidase-IV is a potential molecular biomarker in diabetic kidney disease.

The present study was designed to identify the changes in microvesicle-dipeptidyl peptidase-IV (DPP IV) levels in human urine and serum, and to determine whether there were correlations with the severity of diabetic kidney disease (DKD). A total of 127 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according to the urinary albumin/ creatinine ratio (UACR): microalbuminuria group (n = 50); macroalbuminuria group (n = 34) and normoalbuminuria group (n = 43), and 34 age- and sex-matched non-diabetic healthy subjects were selected as controls. Microvesicle-bound DPP IV and free urinary DPP IV were separated by a filtra-centrifugation method. The total microvesicles were captured by a specific monoclonal antibody, AD-1. DPP IV activity was determined by measuring the cleavage of chromogenic free 4-nitroaniline from Gly-Pro-p-nitroanilide at 405 nm with an ELISA plate reader. DPP IV protein levels were determined by ELISA and Western blot. Our results showed that the microvesicle-bound type was the major form of DPP IV in urine; the urinary microvesicle-DPP IV excretion of each T2DM group was significantly higher compared with controls. The urinary microvesicle-DPP IV level was positively correlated with UACR in patients with T2DM. These findings suggest that the urinary level of microvesicle-bound DPP IV is associated with the severity of DKD.