Hand holding a blood glucose meter measuring blood sugar, the background is a stethoscope and chart file

Increased Dietary Intake of L-Arginine Linked to Increased Risk for Type 2 Diabetes

Hand holding a blood glucose meter measuring blood sugar, the background is a stethoscope and chart file

Hand holding a blood glucose meter measuring blood sugar, the background is a stethoscope and chart file

People who consume higher levels of dietary L-arginine, an amino acid involved in the metabolism of glutamate and proline, were found to have an increased risk of developing type 2 diabetes (TD2), according to research results published in BMC Endocrine Disorders. In the context of total protein intake as well as L-arginine-to-protein ratio, however, no association was found between increased L-arginine intake and risk of T2D.

Research has suggested that L-arginine may be involved in nitric oxide-dependent pathways that affect the homeostasis of glucose and insulin. Currently, little data from long-term studies elucidate the effects of L-arginine intake on the risk for T2D.

In a recent prospective cohort study, a team of researchers from Iran examined the potential impact of dietary L-arginine intake on T2D incidence in 2139 adults (mean age, 38.9 years; 54.6% women) who participated in the third phase of the Tehran Lipid and Glucose Study (TLGS) and who did not have T2D at baseline.

The researchers assessed typical daily intake of protein and L-arginine using a 168-item validated food frequency questionnaire. Participants were considered to have developed T2D over the follow-up period if they were using an antidiabetic drug, had a fasting serum glucose of at least 126 mg/dL, and/or had a 2-hour post-challenge glucose level of at least 200 mg/dL.

Over the median 5.8-year follow-up period, the mean daily intake of dietary protein was 77.2±22.4 g, and the mean daily intake of L-arginine was 4.05±1.50 g. Participants with and without diabetes had the same mean daily intake of L-arginine during the study (4.05±1.5 g for each).

In the crude model, the researchers found no significant association between L-arginine intake and T2D risk in the second tertile (hazard ratio [HR], 0.83; 95% CI, 0.55-1.26) or the third tertile (HR, 1.06; 95% CI, 0.71-1.56) of L-arginine intake (P =.43).

Another analysis was conducted and adjusted for diabetes risk score; physical activity; sex; age; smoking; total energy intake; and intake of carbohydrates, fiber, fats, lysine, and total protein. In this adjusted model, there was a significantly increased risk of T2D in the highest L-arginine intake tertile (mean, >5.4 g/d) compared with the lowest tertile (mean, 2.69 g/d; HR, 2.71; 95% CI, 1.20-6.09; P =.02).

In contrast, there was no association between total protein and ratio of L-arginine-to-total protein intake and T2D incidence (HR, 1.89; 95% CI, 0.99-3.60; P =.052).

A limitation of this study was the lack of adjustment for other factors in food sources of L-arginine that could have affected T2D risk. The lack of data about serum L-arginine levels represented another study limitation.

The researchers noted that given the increased interest in ingesting L-arginine as a “dietary supplement, and also the limited data in case of the potential association between dietary L-arginine and cardio-metabolic outcomes especially T2DM, further cohort studies are required to clarify the possible association.”

Reference
Mirmiran P, Bahadoran Z, Gaeini Z, Azizi F. Habitual intake of dietary L-arginine in relation to risk of type 2 diabetes: a prospective study. BMC Endocr Disord. 2021;21(1):113. doi:10.1186/s12902-021-00774-x

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The number of research articles

17 research articles have been published in research journals till now

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The number of Proposals

44 proposals has been approved in Tabari Cohort Research Center till now

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Beginning of the reassessment phase of the Adult Tabari Cohort Study Center

The Adult Cohort Research Center has started its own active phase on 22nd November, 2021. The first participants registered In Tabari Cohort Research Center on Monday, 22nd November, 2021 and the relevant questionnaires have been completed for them after doing routine tests and having breakfast.

Short sleep is associated with higher prevalence and increased predicted risk of cardiovascular diseases in an Iranian population: Fasa PERSIAN Cohort Study

It can be said that short sleep is related to higher prevalence and increased risk of cardiovascular diseases in the Iranian population.

Cardiovascular diseases are the leading cause of death worldwide. One of the common factors that may affect cardiovascular disease risk factors is sleep disorder. Factors affecting a person’s sleep may be different in different cultures. In this research, which was conducted on more than 10,000 residents of the Shasheda region of Fasa. The results showed that people who sleep less than 6 hours have a higher prevalence of cardiovascular diseases, including heart attacks and high blood pressure, than people who sleep 7-8 hours a day. Also, the researchers of this study stated that after calculating the 10-year cardiovascular risk of people, it was observed that people who sleep less than 6 hours have a higher risk of developing cardiovascular diseases in the next 10 years than people who sleep 7-8 hours.

Following the Famenin brucellosis cohort studies

Following the Famenin brucellosis cohort studies, we designed some another research programs to gain more extra data about the risk factors related the Brucellosis disease in Famenin.

Our main projects are as below:

  1. Evaluation of the incidence, relapse, clinical manifestations and complications of brucellosis during two years among participants in the brucellosis cohort study of Famenin.
  2. Confirmation the results of seropositive samples collected from Famenin brucellosis cohort and determination of their species by PCR technique.
  3. Investigation and follow up of brucellosis disease in seropositive participants in Famenin cohort of brucellosis and their families using culture and serology methods.
  4. A survey of seroprevalence of brucellosis in domestic livestock (cattle, sheep and goats) in Famenin city, 2019.
  5. Evaluation of Brucella infection in milk of domestic animals of Famenin city and its comparison with the results of serological tests in the same animal population.
  6. Investigation and evaluation of dietary exposure to tetracycline, oxitetraciclin and chlortetracycline antibiotic residues in domestic animal’s milk in Famenin.
  7. Isolation of Brucella bacteria from positive serological samples collected from Hamadan province and Famenin brucellosis cohort by culture and genetically confirmation and determination of their species by PCR technique.
addiction

Validity of self-reported substance use: research setting versus primary health care setting

addiction

Abstract

Background: Self-reported substance use is more likely to be influenced by underreporting bias compared to the biological markers. Underreporting bias or validity of self-reported substance use depends on the study population and cannot be generalized to the entire population. This study aimed to compare the validity of self-reported substance use between research setting and primary health care setting from the same source population.

Methods and materials: The population in this study included from Rafsanjan Youth Cohort Study (RYCS) and from primary care health centers. The sample from RYCS is made up 607 participants, 113 (18.62%) women and 494 (81.38%) men and sample from PHC centers is made up 522 individuals including 252 (48.28%) women and 270 (51.72%) men. We compared two groups in respect of prevalence estimates based on self-reported substance use and urine test. Then for evaluating validity of self-reported substance use in both group, the results of reference standard, urine tests, were compared with the results of self-reported drug use using measures of concordance.

Results: The prevalence of substance use based on urine test was significantly higher in both settings compared to self-reported substance use over the past 72 h. The sensitivity of self-report substance use over the past 72 h in research setting was 39.4, 20, 10% and zero for opium, methadone, cannabis and amphetamine, respectively and in primary health care setting was 50, 20.7, 12.5% and zero for opium, methadone, cannabis and amphetamine, respectively. The level of agreement between self-reported substance use over the past 72 h and urine test indicated fair and moderate agreement for opium in both research and primary health care settings, respectively and also slight agreement for methadone and cannabis in both settings were reported. There was no significant difference between the two groups in terms of self-reported substance use. For all substances, the level of agreement increased with longer recall periods. The specificity of self-report for all substances in both groups was more than 99%.

Conclusion: Individuals in primary health care setting were more likely to self-reported substance use than in research setting, but setting did not have a statistically significant effect in terms of self-reported substance use. Programs that rely on self-reported substance use may not estimate the exact prevalence of substance use in both research and primary health care settings, especially for substances that have a higher social stigma. Therefore, it is recommended that self-report and biological indicators be used for more accurate evaluation in substance use studies. It is also suggested that future epidemiological studies be performed to reduce bias of social desirability and find a method providing the highest level of privacy.

Keywords: Primary health care settings; Research setting; Self-reported; Substance use; Underreporting; Validity.

Blood pressure

Hypertension, as a risk factor for cardiovascular diseases, is highly influenced by dietary parameters. This study aims to investigate the possible association of hypertension prevalence and nut consumption.

Blood pressure

In this cross-sectional study, 9990 participants from the Rafsanjan cohort study, as a part of the prospective epidemiological research studies in IrAN (PERSIAN), aged 35-70 years were included. Nut consumption was assessed using an abbreviated food questionnaire. Further, demography, personal habit, physical activity, medical history, blood pressure, and body mass index (BMI) questionnaires were used. Logistic regression models were applied to examine the possible relationship between hypertension risk and nut consumption. Statistical analyses were performed using STATA statistical software.

The results showed that the average consumption of all nuts except walnuts was significantly higher in non-hypertensive individuals (P<0.001). In the crude regression model, the odds of hypertension were significantly lower among pistachio, walnuts, seeds, and total nuts consumers. However, a protective association was observed between the prevalence of hypertension and the consumption of all nuts together and seeds, after adjusting for sex, age, and other confounders.

The data show that the intake of all nuts and seeds is inversely associated with hypertension risk.

cohort birth

cohort birth rafsanjan

The birth cohort from 1397 to 1400 examined about 1500 mothers and babies in Rafsanjan city.

cohort birth