ABSTRACT
BACKGROUND: Hyperhomocysteinemia has been repeatedly found to increase the risk of dementia. However, the effects of hypohomocysteinemia on the risk of dementia have been barely investigated. If hypohomocysteinemia, like hyperhomocysteinemia, increases the risk of dementia, misuse or overuse of homocysteine-lowing agents such as vitamin supplements may increase the risk of dementia. AIMS: To investigate whether hypohomocysteinemia, like hyperhomocysteinemia, could increase the risk of dementia and Alzheimer's disease (AD) in a large population-based cohort of older adults. METHODS: This prospective cohort study followed 2655 randomly sampled, community-dwelling, non-demented individuals aged 60 years or older from 2010 to 2018. We measured baseline serum total homocysteine (tHcy) levels and examined the effect of serum tHcy on the risks of dementia and AD using Cox proportional hazards models. RESULTS: During the follow-up period (mean = 5.4 years, SD = 0.9), dementia and AD developed in 85 and 64 participants, respectively. Not only the participants with high serum tHcy (≥10.6 µmol/L) but also those with low serum tHcy (≤8.9 µmol/L) were 4-5 times more likely to develop dementia and AD compared to those with serum tHcy levels between 9.0 and 10.5 µmol/L. With the increase in serum tHcy concentration, the use of vitamin supplements decreased, and 41.2% of the participants with low serum tHcy (≤8.9 µmol/L) were taking vitamin supplements. CONCLUSIONS: Not only hyperhomocysteinemia but also hypohomocysteinemia considerably increased the risk of dementia and AD in older adults. The risk of dementia that results from overuse or misuse of vitamin supplements should be acknowledged and homocysteine-lowering health policies should be tailored to consider dementia risks that are associated with hypohomocysteinemia.
Subject(s)
Alzheimer Disease/etiology , Dementia/etiology , Dietary Supplements/adverse effects , Homocysteine/blood , Homocysteine/deficiency , Aged , Alzheimer Disease/blood , Alzheimer Disease/epidemiology , Dementia/blood , Dementia/epidemiology , Female , Humans , Independent Living/psychology , Male , Middle Aged , Proportional Hazards Models , Prospective StudiesABSTRACT
BACKGROUND: Colistin is increasingly used as the last therapeutic option for the treatment of multidrug-resistant, Gram-negative bacterial infections. To ensure safe and efficacious use of colistin, therapeutic drug monitoring (TDM) is needed due to its narrow therapeutic window. This study aimed to evaluate the pharmacokinetic (PK) characteristics of colistin and to guide TDM in colistin-treated patients in Korea. METHODS: In a prospective study, we analyzed PK characteristics in 15 patients who intravenously received colistin methanesulfonate twice per day. Colistin methanesulfonate doses were adjusted based on renal function of the subjects. The appropriate blood sampling points for TDM were evaluated by analyzing the correlations between the PK parameters and the plasma concentrations at each time point. RESULTS: The mean values for the minimum, maximum, and average concentrations (Cmin, Cmax, and Caverage) of colistin at steady state were 2.29, 5.5, and 3.38 mg/L, respectively. The dose-normalized Cmin, Cmax, Caverage, and area under the plasma concentration-time curve from 0 to the last measurable concentration (AUClast) showed negative correlations with the creatinine clearance. The combination of the 0- and 2-hour post-dose plasma concentrations was evaluated as the appropriate sampling point for TDM. Two patients reported nephrotoxic adverse events during colistin administration. CONCLUSIONS: Our study clarifies the PK characteristics of successful colistin treatment using TDM. Further evaluations in a larger patient population are needed to confirm the clinical usefulness of colistin TDM.
Subject(s)
Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/therapeutic use , Colistin/pharmacokinetics , Colistin/therapeutic use , Drug Resistance, Multiple, Bacterial/drug effects , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/metabolism , Adult , Aged , Aged, 80 and over , Drug Monitoring/methods , Female , Humans , Infusions, Intravenous/methods , Male , Microbial Sensitivity Tests/methods , Middle Aged , Prospective Studies , Republic of KoreaSubject(s)
Asian People/genetics , Electron-Transferring Flavoproteins/genetics , Iron-Sulfur Proteins/genetics , Multiple Acyl Coenzyme A Dehydrogenase Deficiency/diagnosis , Oxidoreductases Acting on CH-NH Group Donors/genetics , Base Sequence , Carnitine/administration & dosage , Carnitine/analogs & derivatives , Carnitine/analysis , DNA Mutational Analysis , Dietary Supplements , Gene Deletion , Humans , Infant, Newborn , Male , Multiple Acyl Coenzyme A Dehydrogenase Deficiency/drug therapy , Multiple Acyl Coenzyme A Dehydrogenase Deficiency/genetics , Pedigree , Republic of Korea , Riboflavin/therapeutic use , Tandem Mass SpectrometryABSTRACT
Lysinuric protein intolerance (LPI) is a rare inherited metabolic disease, caused by defective transport of dibasic amino acids. Failure to thrive, hepatosplenomegaly, hematological abnormalities, and hyperammonemic crisis are major clinical features. However, there has been no reported Korean patient with LPI as of yet. We recently encountered a 3.7-yr-old Korean girl with LPI and the diagnosis was confirmed by amino acid analyses and the SLC7A7 gene analysis. Her initial chief complaint was short stature below the 3rd percentile and increased somnolence for several months. Hepatosplenomegaly was noted, as were anemia, leukopenia, elevated levels of ferritin and lactate dehydrogenase, and hyperammonemia. Lysine, arginine, and ornithine levels were low in plasma and high in urine. The patient was a homozygote with a splicing site mutation of IVS4+1G > A in the SLC7A7. With the implementation of a low protein diet, sodium benzoate, citrulline and L-carnitine supplementation, anemia, hyperferritinemia, and hyperammonemia were improved, and normal growth velocity was observed.