The prescribing of Chinese herbal products in Taiwan: a cross-sectional analysis of the national health insurance reimbursement database

Increased risk for invasive breast cancer associated with hormonal therapy: a nation-wide random sample of 65,723 women followed from 1997 to 2008

Background

Hormonal therapy (HT) either estrogen alone (E-alone) or estrogen plus progesterone (E+P) appears to increase the risk for breast cancer in Western countries. However, limited information is available on the association between HT and breast cancer in Asian women characterized mainly by dietary phytoestrogens intake and low prevalence of contraceptive pills prescription.

Methodology

A total of 65,723 women (20–79 years of age) without cancer or the use of Chinese herbal products were recruited from a nation-wide one-million representative sample of the National Health Insurance of Taiwan and followed from 1997 to 2008. Seven hundred and eighty incidents of invasive breast cancer were diagnosed. Using a reference group that comprised 40,052 women who had never received a hormone prescription, Cox proportional hazard models were constructed to determine the hazard ratios for receiving different types of HT and the occurrence of breast cancer.

Conclusions

5,156 (20%) women ever used E+P, 2,798 (10.8%) ever used E-alone, and 17,717 (69%) ever used other preparation types. The Cox model revealed adjusted hazard ratios (HRs) of 2.05 (95% CI 1.37–3.07) for current users of E-alone and 8.65 (95% CI 5.45–13.70) for current users of E+P. Using women who had ceased to take hormonal medication for 6 years or more as the reference group, the adjusted HRs were significantly elevated and greater than current users and women who had discontinued hormonal medication for less than 6 years. Current users of either E-alone or E+P have an increased risk for invasive breast cancer in Taiwan, and precautions should be taken when such agents are prescribed.

Use of Chinese Medicine Among Survivors of Nasopharyngeal Carcinoma in Taiwan

Hypotheses. The authors hypothesized that the use of alternative medicine, in the form of Chinese medicine (CM), among patients in the continuing care phase of nasopharyngeal carcinoma (NPC) in Taiwan is higher than the use in a matched control group of noncancer individuals. Study design. This was a case-control study. Methods. Using a population-based claim database, the authors identified 181 long-term survivors of NPC and 905 matched controls. They obtained information on CM use and associated cost as outcome measures. Descriptive analysis and regression models were applied to examine the association between NPC and the outcome measures. Results. The unadjusted CM initiation (34% vs 32%; P = .54), intensity of use (2.15 vs 1.73 visits; P = .37), and cost (US$79 vs US$58; P = .16) were higher for patients in the NPC group than for those in the control group. Regression analyses suggested that the NPC group had significantly more CM visits (1.01; 95% confidence interval = 0.07-1.96), and more than 50% of these visits were related to cancer. Conclusion. The authors confirmed their hypotheses that the use of CM in the continuing care phase by patients with NPC in Taiwan was higher than the use in their matched, noncancer counterparts. These findings suggest that current clinical surveillance strategies for NPC might not meet patients’ physical and emotional needs.

Epigenetics in traditional chinese pharmacy: a bioinformatic study at pharmacopoeia scale

Epigenetics is a phenomenon of heritable changes in the chromatin structure of a genomic region, resulting in a transcriptional silent or active state of the region over cell mitosis. Mounting evidence has demonstrated phenotypic consequence of alternations in the patterns of DNA methylation and histone modifications, two of the well-studied epigenetic mechanisms. The epigenome thus represents an interesting therapeutic target. Traditional Chinese medicine (TCM) is a system of therapies that has developed through empiricism for over 2100 years and has remained a popular alternative medicine in some Far East Asian populations. We searched 3294 TCM medicinals (TCMMs) containing 48 491 chemicals for chemicals that interact with the epigenetics-related proteins and found that 29.8% of the TCMMs are epigenome- and miRNA-modulating via, mainly, interactions with Polycomb group and methyl CpG-binding proteins. We analyzed 200 government-approved TCM formulas (TCMFs) and found that a statistically significant proportion (99%) of them are epigenome- and miRNA-interacting. The epigenome and miRNA interactivity of the Monarch medicinals is found to be most prominent. Histone modifications are heavily exploited by the TCMFs, many of which are tonic. Furthermore, epigenetically, the Assistant medicinals least resemble the Monarch. We quantified the role of epigenetics in TCM prescription and found that epigenome- and miRNA-interaction information alone determined, to an extent of 20%, the clinical application areas of the TCMFs. Our results provide (i) a further support for the notion of the epigenomes as a drug target and (ii) a new set of tools for the design of TCM prescriptions.

Population-based case-control study of Chinese herbal products containing aristolochic acid and urinary tract cancer risk

Background

Consumption of Chinese herbs that contain aristolochic acid (eg, Mu Tong) has been associated with an increased risk of urinary tract cancer.

Methods

We conducted a population-based case–control study in Taiwan to examine the association between prescribed Chinese herbal products that contain aristolochic acid and urinary tract cancer. All patients newly diagnosed with urinary tract cancer (case subjects) from January 1, 2001, to December 31, 2002, and a random sample of the entire insured population from January 1, 1997, to December 31, 2002 (control subjects), were selected from the National Health Insurance reimbursement database. Subjects who were ever prescribed more than 500 pills of nonsteroidal anti-inflammatory drugs and/or acetaminophen were excluded, leaving 4594 case patients and 174 701 control subjects in the final analysis. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multivariable logistic regression models for the association between prescribed Chinese herbs containing aristolochic acid and the occurrence of urinary tract cancer. Models were adjusted for age, sex, residence in a township where black foot disease was endemic (an indicator of chronic arsenic exposure from drinking water [a risk factor for urinary tract cancer]), and history of chronic urinary tract infection. Statistical tests were two-sided.

Results

Having been prescribed more than 60 g of Mu Tong and an estimated consumption of more than 150 mg of aristolochic acid were independently associated with an increased risk for urinary tract cancer in multivariable analyses (Mu Tong: at 61–100 g, OR = 1.6, 95% CI = 1.3 to 2.1, and at >200 g, OR = 2.1, 95% CI = 1.3 to 3.4; aristolochic acid: at 151–250 mg, OR = 1.4, 95% CI = 1.1 to 1.8, and at >500 mg, OR = 2.0, 95% CI = 1.4 to 2.9). A statistically significant linear dose–response relationship was observed between the prescribed dose of Mu Tong or the estimated cumulative dose of aristolochic acid and the risk of urinary tract cancer (P < .001 for both).

Conclusions

Consumption of aristolochic acid–containing Chinese herbal products is associated with an increased risk of cancer of the urinary tract in a dose-dependent manner that is independent of arsenic exposure.

Increased risks of chronic kidney disease associated with prescribed Chinese herbal products suspected to contain aristolochic acid

AIM

Nephropathy associated with aristolochic acid (AA) has been documented by human and animal studies. Ancient Chinese herbology claimed to reduce toxicity in their mixtures. It was the objective of this study to determine the risk of chronic kidney disease (CKD) associated with AA-related Chinese herbal products (CHP) or mixtures of herbs in a national cohort.

METHODS

A retrospective follow-up study was conducted, using a systematic random sample (200 000 people) in the National Health Insurance reimbursement database during 1997-2002. The incidence rates of CKD and end-stage renal disease (ESRD) were calculated for the whole sample and those that had used CHP suspected to contain AA. Cox regression models were constructed to control potential confounders, including age, sex, hypertension, diabetes mellitus, and use of non-steroidal anti-inflammatory drugs and acetaminophen.

RESULTS

A total of 199 843 persons were included in the final analysis, 102 464 (51.3%) men and 97 379 (48.7%) women, with an average incidence rate of 1964/10(6) person-years for CKD and 279/10(6) person-years for ESRD. After controlling other risk factors, the hazard ratios for development of CKD seemed to increase for patients that had consumed more than 30 g Mu-Tong, and more than 60 g Fangchi.

CONCLUSION

Prescription of more than 30 g Mu-Tong or more than 60 g Fangchi CHP was associated with an increased risk of developing CKD. In addition to prohibiting the use of Guan-Mu-Tong and Guang-Fangchi, patients who have used these CHP should continue to be followed up.

Prescription profile of potentially aristolochic acid containing Chinese herbal products: an analysis of National Health Insurance data in Taiwan between 1997 and 2003

Background

Some Chinese herbal products (CHPs) may contain aristolochic acid (AA) or may be adulterated by the herbs suspected of containing AA which is nephrotoxic and carcinogenic. This study aims to identify the risk and the prescription profile of AA-containing CHPs (AA-CHPs) in Taiwan.

Methods

A longitudinal analysis was conducted on a randomly sampled cohort of 200,000 patients using the data from the National Health Insurance (NHI) in Taiwan between 1997 and 2003.

Results

During the 7-year study period, 78,644 patients were prescribed with AA-CHPs; most patients were females, or middle-aged, or both. A total of 526,867 prescriptions were made to use 1,218 licensed AA-CHPs. Over 85% of the AA-exposed patients took less than 60 g of AA-herbs; however, about 7% were exposed to a cumulated dose of over 100 g of Radix et Rhizoma Asari (Xixin), Caulis Akebiae (Mutong) or Fructus Aristolochiae (Madouling). Patients of respiratory and musculoskeletal diseases received most of the AA-CHP prescriptions. The most frequently prescribed AA-CHPs Shujing Huoxie Tang, Chuanqiong Chadiao San and Longdan Xiegan Tang, containing Radix Stephaniae Tetrandrae, Radix et Rhizoma Asari and Caulis Akebiae, respectively.

Conclusion

About one-third of people in Taiwan have been prescribed with AA-CHPs between 1997 and 2003. Although the cumulated doses were not large, further actions should be carried out to ensure the safe use of AA-CHPs.