Microwave photonics doppler speed measurement based on sagnac loops and four-wave mixing effect in a highly nonlinear fiber

Photonic radars are increasingly being developed and offer a promising replacement for traditional RF radars. They feature higher precision, and smaller size compared to the current microwave radars. One important part of a moving target indicating (MTI) radar is the Doppler shift measurement used to measure the radial velocity of a moving target. Therefore, for any photonic radar operating at MTI mode, it is necessary to have a Doppler measurement subsystem. In this paper, a microwave photonic Doppler frequency measurement system is conceived and implemented for this purpose specifically. The operation is based on making a Doppler shift-dependent yet low-frequency voltage component. It is all-optical and hence has the potential to be integrated into many electronic warfare systems. This feature not only makes the system independent of any sophisticated electrical device but also makes the measurement time lower than that of the electrical counterparts. The specific design presented here provides a much better stability compared to the recent works. An error as low as 0.012 Hz at a 10 GHz radar frequency was obtained, and the system performance was demonstrated up to 40 GHz, at which a 4.75 Hz error was recorded.

Platelets regulate ischemia-induced revascularization and angiogenesis by secretion of growth factor-modulating factors

In ischemic tissue, platelets can modulate angiogenesis. The specific factors influencing this function, however, are poorly understood. Here, we characterized the complement anaphylatoxin C5a-mediated activation of C5a receptor 1 (C5aR1) expressed on platelets as a potent regulator of ischemia-driven revascularization. We assessed the relevance of the anaphylatoxin receptor C5aR1 on platelets in patients with coronary artery disease as well as those with peripheral artery disease and used genetic mouse models to characterize its significance for ischemia and growth factor-driven revascularization. The presence of C5aR1-expressing platelets was increased in the hindlimb ischemia model. Ischemia-driven angiogenesis was significantly improved in C5aR1-/- mice but not in C5-/- mice, suggesting a specific role of C5aR1. Experiments using the supernatant of C5a-stimulated platelets suggested a paracrine mechanism of angiogenesis inhibition by platelets by means of antiangiogenic CXC chemokine ligand 4 (CXCL4, PF4). Lineage-specific C5aR1 deletion verified that the secretion of CXCL4 depends on C5aR1 ligation on platelets. Using C5aR1-/-CXCL4-/- mice, we observed no additional effect in the revascularization response, underscoring a strong dependence of CXCL4 secretion on the C5a-C5aR1-axis. We identified a novel mechanism for inhibition of neovascularization via platelet C5aR1, which was mediated by the release of antiangiogenic CXCL4.

Effect of Ca(NO3)2 coating on chemical and mechanical properties and bruise susceptibility of Golden Delicious and Red Delicious apples during storage

Effect of coating with calcium nitrate in three concentrations (0.0, 0.5, and 1.0 wt%) on chemical and mechanical properties, and impact behaviour of two apple cultivars (Golden Delicious (GD) and Red Delicious (RD)) during time (0, 2, and 4 months) was studied. Moisture content, pH, titratable acidity, °Brix, organoleptic properties, modulus of elasticity (E), yield stress, yield strain, and toughness were measured. The effect of impact loads was determined by measuring bruise volume (BV) and bruise susceptibility (BS). The results showed that pH and °Brix significantly increased, while titratable acidity, E, yield strain, toughness, and BV decreased during storage time. As Ca(NO3)2 concentration increased, titratable acidity, E, yield strain and yield stress increased and pH decreased (P < 0.05). Highest and lowest values for °Brix were observed in GD treated with 1.0% Ca(NO3)2 after four months (13.31) and GD treated with 0.5% Ca(NO3)2 at the first day (10.65), respectively. Maximum E was obtained in GD treated with 1.0% Ca(NO3)2 on the first day (2130 kPa) and this sample also showed the lowest BS after four months of storage (2.82 mL J−1), while the uncoated GD had the highest BS on the first day (7.11 mL J−1).

Transcriptomic analysis of poco1, a mitochondrial pentatricopeptide repeat protein mutant in Arabidopsis thaliana

BACKGROUND

Flowering is a crucial stage during plant development. Plants may respond to unfavorable conditions by accelerating reproductive processes like flowering. In a recent study, we showed that PRECOCIOUS1 (POCO1) is a mitochondrial pentatricopeptide repeat (PPR) protein involved in flowering time and abscisic acid (ABA) signaling in Arabidopsis thaliana. Here, we use RNA-seq data to investigate global gene expression alteration in the poco1 mutant.

RESULTS

RNA-seq analysis was performed during different developmental stages for wild-type and poco1 plants. The most profound differences in gene expression were found when wild-type and poco1 plants of the same developmental stage were compared. Coverage analysis confirmed the T-DNA insertion in POCO1, which was concomitant with truncated transcripts. Many biological processes were found to be enriched. Several flowering-related genes such as FLOWERING LOCUS T (FT), which may be involved in the early-flowering phenotype of poco1, were differentially regulated. Numerous ABA-associated genes, including the core components of ABA signaling such as ABA receptors, protein phosphatases, protein kinases, and ABA-responsive element (ABRE) binding proteins (AREBs)/ABRE-binding factors (ABFs) as well as important genes for stomatal function, were mostly down-regulated in poco1. Drought and oxidative stress-related genes, including ABA-induced stress genes, were differentially regulated. RNA-seq analysis also uncovered differentially regulated genes encoding various classes of transcription factors and genes involved in cellular signaling. Furthermore, the expression of stress-associated nuclear genes encoding mitochondrial proteins (NGEMPs) was found to be altered in poco1. Redox-related genes were affected, suggesting that the redox state in poco1 might be altered.

CONCLUSION

The identification of various enriched biological processes indicates that complex regulatory mechanisms underlie poco1 development. Differentially regulated genes associated with flowering may contribute to the early-flowering phenotype of poco1. Our data suggest the involvement of POCO1 in the early ABA signaling process. The down-regulation of many ABA-related genes suggests an association of poco1 mutation with the ABA signaling deficiency. This condition further affects the expression of many stress-related, especially drought-associated genes in poco1, consistent with the drought sensitivity of poco1. poco1 mutation also affects the expression of genes associated with the cellular regulation, redox, and mitochondrial perturbation.

PRECOCIOUS1 (POCO1), a mitochondrial pentatricopeptide repeat protein affects flowering time in Arabidopsis thaliana

Flowering is a vital developmental shift in plants from vegetative to reproductive phase. The timing of this shift is regulated by various linked genetic pathways including environmental cues and internal regulation. Here we report a role for an Arabidopsis gene, AT1G15480, which encodes a P-class pentatricopeptide repeat (PPR) protein, affecting flowering time. We show that AT1G15480 is localized to mitochondria. An AT1G15480 T-DNA insertion line exhibits an early-flowering phenotype, which is quite a rare phenotype among PPR mutants. The early-flowering phenotype was observed under both long and short days compared with wild type plants. Genetic complementation confirmed the observed phenotype. We therefore named the PPR protein PRECOCIOUS1 (POCO1). poco1 plants showed lower respiration, ATP content and higher accumulation of superoxide. Importantly, the quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that the expression of FLOWERING LOCUS C (FLC), which is a key floral repressor, was strongly downregulated in the poco1. Likewise, the expression level of the FLC positive regulator ABSCISIC ACID-INSENSITIVE 5 (ABI5) was reduced in the poco1. Consistent with the qRT-PCR results, poco1 plants showed reduced sensitivity to abscisic acid compared with wild type with respect to primary root growth and days to flowering. Furthermore, the poco1 mutation enhances the sensitivity to drought stress. Further analysis showed that POCO1 affects mitochondrial RNA editing. Taken together, our data demonstrate a remarkable function of POCO1 in flowering time and the abscisic acid signalling pathway.

Microwave photonics instantaneous frequency measurement receiver based on a Sagnac Loop: publisher's note

This publisher's note amends the author listing in Opt. Lett.43, 2233 (2018).OPLEDP0146-959210.1364/OL.43.002233.

Microwave photonics instantaneous frequency measurement receiver based on a Sagnac loop

A microwave photonics instantaneous frequency measurement receiver was conceived and practically demonstrated. The system is based on phase modulation inside a Sagnac loop and therefore needs no bias voltage, resulting in no DC bias drifts. The system provides a DC output whose amplitude is a function of input signal frequency, and thus no high-frequency photo-detector is required. Furthermore, the system exhibits a very good sensitivity without the aid of any sort of electrical noise cancellation techniques, such as lock-in amplification. This makes the system response faster, which would be another benefit for electronic warfare applications. Less than 6% measurement error was achieved over a 0.01-40 GHz frequency range for -30  dBm RF level. Also, a 10% error was achieved at -51  dBm RF power level.

Cigarette smoking in patients newly diagnosed with pulmonary tuberculosis in Iran

BACKGROUND

The association between pulmonary tuberculosis (PTB) and tobacco smoke has been verified by most studies on the subject; figures from different countries for the prevalence of smoking among PTB patients vary.

OBJECTIVE

To assess the prevalence of and factors associated with smoking among TB patients in Iran.

DESIGN

In this cross-sectional study, subjects were included on a first-come, first-served basis from among newly diagnosed PTB patients using a multistage cluster sampling method during 2012-2014. Data were collected during face-to-face interviews and a questionnaire was used to gather information on smoking habits.

RESULTS

Of 1127 newly diagnosed PTB patients included in the study (mean age 50.0 ± 19.8 years), 228 (20.2%) were daily smokers, 20 (1.8%) were occasional smokers and 93 (8.9%) had quit before diagnosis. Simultaneous drug use (P < 0.001, OR 75.21), increasing age (P = 0.001), being single (P < 0.001, OR 16.95), being an Iranian national (P < 0.001, OR 6.26) and living in a rural area (P < 0.001, OR 5.85) were found to be independent risk factors for smoking in study patients.

CONCLUSION

The prevalence of smoking among PTB patients in Iran is relatively high. It is therefore necessary to include smoking cessation interventions in the National TB Programme.

Rhabdomyolysis among acute human poisoning cases

Rhabdomyolysis is a clinical and biochemical syndrome occurring when skeletal muscle cells erupt and result in release of creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and myoglobin into the interstitial space and plasma. Mechanical trauma, compression, excessive muscle activity and ischemia are frequent causes, but non-traumatic rhabdomyolysis is usually caused by a toxic reaction to drugs.

In this study, 181 patients suspected of rhabdomyolysis were admitted to the poisoning center of Loghman-Hakim Hospital in Tehran during one year (September 2004 to September 2005) were studied. Patients were included on the basis of physical examination and blood analysis for CPK and LDH. Rhabdomyolysis was confirmed if CPK level has been greater than 975 U/L. Out of 181 patients, 64 were female and 117 were male with an age range between 13—78 years. One-hundred and forty-three (79%) patients had CPK greater than 975 U/L. In 6% of the cases, multiple drug poisoning were observed. Two patients (1.1%) had muscle pain, five patients (2.8%) had rigidity and five patients (2.8%) had muscle inflammation. One-hundred and nineteen patients (65.7%) were febrile. The most common cause of rhabdomyolysis was opium. Blood ALT showed an increase in 109 patients (60.9%), AST in 80 patients (44.7%), and LDH in 144 patients (79.6%). Fifty patients (28.2%) had higher blood direct bilirubin and 64 patients (36.4%) showed higher total bilirubin. Six percent of patients had been diagnosed as ARF by indication of creatinine greater than 1.4 mg/dL. Five percent of patients had hypernatremia and 1.1% of patients had hyperkalemia.

It is concluded that rhabdomyolysis is a matter of concern in human poisonings and needs special approach to attend. Human & Experimental Toxicology (2007) 26: 557—561.

Risk Factors for Lung Cancer Mortality in a Referral Center

BACKGROUND

Lung cancer is one of the most common causes of death that is rising in many countries including Iran. This study aimed to determine the impact of factors on survival of lung cancer patients at a referral center of lung diseases in Tehran, Iran.

MATERIALS AND METHODS

A retrospective study was conducted on adult lung cancer cases admitted to a referral center for lung diseases from 2011 to 2015. Multivariate analysis was performed to determine the risk factors for all-cause mortality.

RESULTS

Of a total 933 patients with lung cancer, 53.4% died, 49.3% of them at the hospital. Overall median follow-up time was 7 months. The most common histological type of cancer was adenocarcinoma with a 13 month median survival time. Age ≥55 and smoking remained significant for all-cause mortality on Cox analysis, whereas gender was not.

CONCLUSIONS

The survival of lung cancer patients is poor and the patients with history of smoking and age ≥55 are at increased risk of death. Having a large hospital-based registry provides a good measurement of prognostic statistics for lung cancer. Further investigations are necessary to establish reasons for mortality.

The First Experience of Ex-Vivo Lung Perfusion (EVLP) in Iran: An Effective Method to Increase Suitable Lung for Transplantation

BACKGROUND

Although lung transplantation is a well-accepted treatment for end-stage lung diseases patients, only 15%-20% of the brain-dead donors' lungs are usable for transplantation. This results in high mortality of candidates on waiting lists. Ex-vivo lung perfusion (EVLP) is a novel method for better evaluation of a potential lung for transplantation.

OBJECTIVE

To report the first experience of EVLP in Iran.

METHODS

The study included a pig in Vienna Medical University, Vienna, Austria, and 4 humans in Masih Daneshvari Hospital, Tehran, Iran. All brain-dead donors from 2013 to 2015 in Tehran were evaluated for EVLP. Donors without signs of severe chest trauma or pneumonia, with poor oxygenation were included.

RESULTS

An increasing trend in difference between the pulmonary arterial pO₂ and left atrial pO₂, an increasing pattern in dynamic lung compliance, and a decreasing trend in the pulmonary vascular resistance, were observed.

CONCLUSION

The initial experience of EVLP in Iran was successful in terms of important/critical parameters. The results emphasize on some important considerations such as precisely following standard lung harvesting and monitoring temperature and pressure. EVLP technique may not be a cost-effective option for low-income countries at first glance. However, because this is the only therapeutic treatment for end-stage lung disease, it is advisable to continue working on this method to find alternatives with lesser costs.

Reconfigurable microwave photonic in-phase and quadrature detector for frequency agile radar

A microwave photonic in-phase and quadrature detector is conceived and practically demonstrated. The detector has the ability to become electronically reconfigured to operate at any frequency over a wide range. This makes it an excellent candidate for frequency agile radars and other electronic warfare systems based on frequency hopping. The detector exhibits a very low amplitude and phase imbalance, which removes the need for any imbalance compensation technique. The system is designed based on the transversal filtering concept and reconfigurability is achieved via wavelength control in a dispersive fiber. The system operation was demonstrated over a frequency range of 3.5-35 GHz, with a maximum of -32 dB amplitude imbalance.

Comparing omeprazole with fluoxetine for treatment of patients with heartburn and normal endoscopy who failed once daily proton pump inhibitors: double-blind placebo-controlled trial

BACKGROUND

Patients with heartburn but without esophageal erosion respond less well to proton pump inhibitors (PPIs). There is a growing body of evidence implicating the role of psychological comorbidities in producing reflux symptoms. Pain modulators improve symptoms in patients with other functional gastrointestinal disorders. We aimed to compare the efficacy of fluoxetine with omeprazole and placebo to achieve symptomatic relief in patients with heartburn and normal endoscopy who failed once daily PPIs.

METHODS

Endoscopy-negative patients with heartburn who failed once daily PPIs were randomly allocated to receive 6 weeks treatment of fluoxetine, omeprazole, or placebo. Random allocation was stratified according to ambulatory pH monitoring study. Percentage of heartburn-free days and symptom severity was assessed.

KEY RESULTS

Sixty patients with abnormal and 84 patients with normal pH test were randomized. Subjects receiving fluoxetine experienced more improvement in percentage of heartburn-free days (median 35.7, IQR 21.4-57.1) than those on omeprazole (median 7.14, IQR 0-50, p < 0.001) or placebo (median 7.14, IQR 0-33.6, p < 0.001). In normal pH subgroup, fluoxetine was superior to both omeprazole and placebo regarding percentage of heartburn-free days (median improvement, 57.1, IQR 35.7-57.1 vs 13.9, IQR, 0-45.6 and 7.14, 0-23.8, respectively, p < 0.001), but no significant difference was observed between medications in abnormal pH subgroup.

CONCLUSIONS & INFERENCES

Fluoxetine was superior to omeprazole for improving the symptoms of patients with heartburn and normal endoscopy who failed once daily PPIs. The superiority of fluoxetine was mostly attributed to those with normal esophageal pH rather than those with abnormal pH (ClinicalTrials.gov, number NCT01269788).

Broadband all-optical microwave photonics phase detector

A microwave photonics phase detector is conceived and practically demonstrated. The phase-detector system employs a semiconductor optical amplifier as a four-wave mixer to enable phase detection over a broad frequency range. The system behavior is first mathematically modeled and then demonstrated practically. Phase measurement over a frequency range of 1-18 GHz is achieved. This phase detector is an excellent candidate for wideband applications such as frequency-agile radar.

Photonic simultaneous frequency identification of radio-frequency signals with multiple tones

A photonic approach to instantaneously identify frequency components of microwave signals with multiple tones is conceived and practically demonstrated. A mathematical model was first developed to predict the behavior of the system. Then the system operation was tested in practice. The system employs a double mixing technique that enables high-frequency measurement without the need for any high-frequency RF component or broadband photodetector. The system operation was demonstrated over a frequency range of 0.1-40 GHz. Frequency measurement of two simultaneous RF tones is demonstrated; however, the system has the potential to be expanded to measure a larger number of simultaneous RF tones. It also has the potential to operate over a wider frequency range.

Reconfigurable photonic radar warning receiver based on cascaded grating

A photonic radar warning receiver was conceived and practically demonstrated. The system was very flexible in terms of frequency measurement range and resolution. This was achieved using a cascaded grating which provided different time delays for different wavelengths. The system was thus able to become reconfigured to operate at both broadband, low resolution and narrow band, high resolution modes.

Abstract P2-12-10: Psycho-spiritual therapy for improving the quality of life and spiritual well-being of women with breast cancer

Objective: Psychological distress and morbidity are common consequences of diagnosis and treatment of breast cancer and associated with poor quality of life (QOL). Among several approaches, spirituality has been shown to be significantly associated with improving the quality of life of these patients. The aim of this study was to assess the role of psycho-spiritual therapy intervention in improving the quality of life and spiritual well-being of patients with breast cancer.

Methods: This was a randomized controlled trial study which was conducted in the Breast Cancer Research Center, St. S. Al-Shohada hospital, Isfahan, Iran. Sixty-eight patients with breast cancer were randomized to either psycho-spiritual therapy intervention group or control group who received routine management and educational programs. Before and after 6 weeks of psycho-spiritual therapy sessions, the quality of life was evaluated using Cancer quality-of-life questionnaire (QLQ-C30) and its supplementary breast cancer questionnaire (QLQ-BR23) and Spiritual well-being was measured using the Functional Assessment of Chronic Illness Therapy Spiritual Well-being scale (FACIT-Sp12). Multivariate, repeated-measures ANOVA, T-test and Paired T-test were used for analysis using Predictive Analytic Soft Ware (PASW, version 18) for windows.

Results: In all sixty five patients actually completed the six-week intervention and were evaluated for the outcomes. The mean Global health status score/QOL reached from 44.37 (SD: 13.03) to 68.63 (SD: 10.86), (p &lt; 0.001), (Cohen's d effect size: 2.16, 95% CI: 1.56–2.78). There was a statistically significant difference in all functional scales of QLQ-C30 (p &lt; 0.05) as well as spiritual well-being after intervention. (p = 0.02)

Conclusions: The results of this trial showed that the psycho-spiritual therapy program can improve the spiritual well-being and QOL of women with breast cancer. This program, with its ease of implementation and home practice, could be adopted in comprehensive care programs for women with breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-12-10.

Common methods to treat addiction in treatment- rehabilitation centers in tehran

BACKGROUND

This study was to determine common methods to treat addiction used by patients checked into Outpatient Treatment and Rehabilitation Clinics in Tehran.

METHODS

The study was conducted in Social Security affiliated outpatient clinics including three governmental and several private centers in 22 districts of Tehran. Demographic data, personal information, social characteristics and information regarding prevention, treatment, and follow-up records of 1,372 patients were obtained and analyzed.

RESULTS

A majority of cases referring to the treatment centers were male (95.2%). Patients were 14 to 75 yr (mean 35.48 ± 10.57 yr); 61.7% were married and lived in rented homes in the city; 938/1372 (68.4%) had at least one previous attempt failure when seeking re-treatment. A majority of them (77.8%) had a history of 1 to 4 quit attempts; a number 63.1% had an abstinence period of 1 week to 6 months.

CONCLUSION

The majority of our understudy subjects had a history of previous attempts to treat their addiction with a maximum abstinence period of 6 months.

Instantaneous frequency measurement system using optical mixing in highly nonlinear fiber

A broadband photonic instantaneous frequency measurement system utilizing four-wave mixing in highly nonlinear fiber is demonstrated. This new approach is highly stable and does not require any high-speed electronics or photodetectors. A first principles model accurately predicts the system response. Frequency measurement responses from 1 to 40 GHz are demonstrated and simple reconfiguration allows the system to operate over multiple bands.

Amplitude independent RF instantaneous frequency measurement system using photonic Hilbert transform

A photonic instantaneous frequency measurement system capable of measuring both RF frequency and power simultaneously, is conceived and practically demonstrated. This system employs an RF photonic Hilbert transformer together with low-cost, low-frequency photo-detectors to obtain two orthogonal DC measurements. This system exhibits a frequency range of 1-10 GHz. Wider frequency range can be achieved through integration.

Wideband RF photonic in-phase and quadrature-phase generation

A photonic implementation of a practical broadband RF Hilbert transformer is demonstrated by using a four-tap transversal system. An almost ideal 90 degrees phase shift with less than 3 dB of amplitude ripple has been achieved from 2.4 to 17.6 GHz. An efficient method to realize both transformed (quadrature-phase) and reference (in-phase) signal has been achieved by using a coarse wavelength division multiplexing coupler. Extension of the transformer bandwidth and further improvements of its implementation are discussed.

Outcome of treatment with 2nd and 3rd generation platinum-based chemotherapy in advanced non-small cell carcinoma (NSCLC): A single institute experience

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Background: The cornerstone of treatment in patients with advanced NSCLC is chemotherapy. During past years 3rd generation cytotoxic drugs have replaced 2nd generation drugs in combination with platinum. Although some trials suggest that newer agents are less toxic and with better response rates compared to older ones, but overall survival outcomes are similar. Methods: Between 1999- 2005, 275 patients with advanced NSCLC (unresectable IIIA, IIIB and IV) have been treated in our center with either frontline 2nd (204 pts.) or 3rd (71 pts.) generation, platinum-based regimens. Retrospectively we analyzed the outcome of treatment (i.e. response rate and overall survival) in these patients according to the generation of chemotherapy regimen. Results: Male/female ratio was 3.6/1 and mean age 58.9. Pathology subtypes includes: adenocarcinoma (49.8%), squamous cell carcinoma (28%), undiff. NSCLC (21.8%) and large cell carcinoma (0.4%). The RR was higher with 3rd generation protocols compared to 2nd generations (47.9% vs 26.5%, P = 0.001) but the median OS in both groups was statistically non-significant (12.07 vs 10.57 m). Analyzing RR and OS in different pathology subtypes shows that in adenocarcinoma and squamous cell ca. the RR is higher with 3rd generation compared to 2nd generation (40.5% vs 20%, P=0.01 & 72.8% vs 27.3%, P=0.005 respectively), but the OS between these two generations was not statistically significant in both pathology subtypes. In undiff. NSCLC the outcome between 2nd and 3rd generation is non-significant in terms of OS and RR. The distribution of different stages in both study groups was statistically similar. Conclusions: Based on this study the 3rd generation protocols in the treatment of advanced NSCLC is superior to 2nd generation protocols in term of RR, although the median OS is statistically non-significant.

No significant financial relationships to disclose.

Serum lipid levels in an Iranian adults population: Tehran Lipid and Glucose Study

Data from 6246 participants aged 20-64 years (2339 males and 3907 females) in the cross-sectional phase of Tehran Lipid and Glucose Study (February 1999-May 2000) were used to determine distribution of serum lipid levels after 12-14 hour overnight fast. Mean total cholesterol (TC) concentration was 210 mg/dl. TC was significantly greater in females than males, 213 and 206 mg/dl, respectively (p < 0.0001). Thirty-one percent of population had TC values between 200 and 239 and 24% had values of 240 mg/dl or greater. Mean low-density lipoprotein cholesterol (LDL-C) was 129 and 135 mg/dl in males and females, respectively (p < 0.0001). Twenty-seven percent had LDL-C values between 130 and 159 and 23% had values 160 mg/dl or greater. The mean triglycerides (TGs) values were 190 and 162 mg/dl for males and females, respectively (p < 0.0001). The mean high-density lipoprotein cholesterol (HDL-C) was 39 in males and 45 mg/dl in females (p < 0.0001). The results showed higher levels of TC, LDL-C and TGs and slightly lower HDL-C in Tehranian adults than other studies in the industrialized countries.

Determinants of serum HDL-C level in a Tehran urban population: the Tehran Lipid and Glucose Study

BACKGROUND AND AIM

Decreased serum high-density lipoprotein cholesterol (HDL-C) is one of the most common lipid disorders in patients with coronary artery disease (CAD). Existing evidence suggests that every 1 mg/dL decrease in serum HDL-C increases the risk of CAD by 2-3%. This study was performed in the year 2000 to study HDL-C determinants in a Tehran population.

METHODS AND RESULTS

We studied 9514 subjects (3942 men and 5572 women) aged 20-69 years, who participated in the Tehran Lipid and Glucose Study (TLGS), completed a personal history questionnaire (especially concerning physical activity and cigarette smoking), and underwent a clinical examination including anthropometric and blood pressure measurements. Serum total cholesterol, triglyceride and HDL-C levels were measured, and OGTT was used to define diabetic patients according to WHO criteria. The women had a significantly higher mean HDL-C level than the mean (45 +/- 11 vs 38 +/- 9 mg/dL; p < 0.001); low HDL-C levels (< 35 mg/dL) were observed in 31% of the men and 13% of the women (p < 0.001). Obese subjects (BMI > or = 30 kg/m2) had a significantly lower HDL-C level than the normal subjects (42 +/- 11 vs 44 +/- 11 mg/dL: p < 0.001), and those with truncal obesity (WHR > or = 0.95 in men and > or = 0.8 in women) lower HDL-C levels than the normal subjects (37 +/- 9 vs 39 +/- 10 mg/dL in men and 44 +/- 11 vs 42 +/- 11 mg/dL in women; p < 0.001 for both). Smokers had a significantly lower HDL-C level than non-smokers (38 +/- 10 vs 43 +/- 11 mg/dL; p < 0.001) and a low HDL-C level was twice as common (36.4 vs 18.2%). Passive smokers also had lower HDL-C levels (42 +/- 11 vs 43 +/- 11 mg/dL; p < 0.001). Mean serum HDL-C was significantly lower in hypertriglyceridemic than those with normal triglycerides levels (men: 4 +/- 8 vs 40 +/- 9 mg/dL, p < 0.001; women: 40 +/- 10 vs 47 +/- 11 mg/dL, p < 0.01). Mean HDL-C levels were similar in subjects with different degrees of physical activity, as well as between diabetics and non-diabetics and hypertensive and normotensive subjects. Multiple stepwise regression analysis showed that the determinants of serum HDL-C levels were, in order of entering the model: hypertriglyceridemia (OR 3.4, p < 0.001), male sex (OR 3.1, p < 0.001), cigarette smoking (OR 1.7, p < 0.001), obesity (OR 1.4, p < 0.01), age (OR 0.9, p < 0.05), high WHR (OR 1.2, p < 0.05), and passive smoking (OR 1.1, p < 0.05). Physical activity, hypertension, and diabetes mellitus did not enter the predictive model.

CONCLUSION

Apart from age and sex which are constitutional, and unmodifiable variables, the determinants of HDL-C level (hypertriglyceridemia, obesity, truncal obesity, cigarette smoking, and passive smoking) can be used in community CAD prevention programmes.