Seasonal variations of lipid profiles in a French cohort

Association between Air Pollution and Lipid Profiles

Dyslipidemia is a critical factor in the development of atherosclerosis and consequent cardiovascular disease. Numerous pieces of evidence demonstrate the association between air pollution and abnormal blood lipids. Although the results of epidemiological studies on the link between air pollution and blood lipids are unsettled due to different research methods and conditions, most of them corroborate the harmful effects of air pollution on blood lipids. Mechanism studies have revealed that air pollution may affect blood lipids via oxidative stress, inflammation, insulin resistance, mitochondrial dysfunction, and hypothalamic hormone and epigenetic changes. Moreover, there is a risk of metabolic diseases associated with air pollution, including fatty liver disease, diabetes mellitus, and obesity, which are often accompanied by dyslipidemia. Therefore, it is biologically plausible that air pollution affects blood lipids. The overall evidence supports that air pollution has a deleterious effect on blood lipid health. However, further research into susceptibility, indoor air pollution, and gaseous pollutants is required, and the issue of assessing the effects of mixtures of air pollutants remains an obstacle for the future.

Association between cold spells and serum lipid levels among the elders: a distributed-lagged effects analysis

Little evidence about the effects of cold spells on serum lipid levels is available. The aim of this study was to explore the association between cold spells and serum lipid levels among the elders in Jinan, China. Data of old adults from health check-up program in Shandong Provincial Qianfoshan Hospital was collected for this study. Linear mixed models combined with distributed lag nonlinear models were used to examine the relationship between cold spells and serum lipid levels, considering the confounding effects of age, sex, blood pressure, body mass index, and other meteorological factors. Subgroup analysis by gender and analysis based on different definitions of cold spells were also conducted. Increased TG levels in lag 0-lag 2 days and decreased TG levels in lag 5-lag 8 days after cold spells were observed among the elders. The largest increase was 0.363 mmol/L (95% CI: 0.184 ~ 0.543) in lag 0 day, while the largest decreased TG levels was 0.083 mmol/L (95% CI: 0.147 ~ 0.019) in lag 6 day. Similar results were obtained in the analysis of different sex and based on different definitions of cold spells. However, no significant association was found between cold spells with TC, LDL-C, and HDL-C. This study indicates that cold spells were significantly associated with serum TG levels in the elders. Effective preventive measures should be implemented around the cold spells to reduce the volatility of serum lipid levels and the occurrence of subsequent cardiovascular diseases.

Data mining: traditional spring festival associated with hypercholesterolemia

BACKGROUND

Serum lipid concentrations are affected by long-term high-fat diets; thus, we hypothesize that lipid levels increase after the Spring Festival in China.

METHOD

In total, 20,192 individuals (male: n=10,108, female: n=10,084) were enrolled in this retrospective cross-sectional study based on clinical data from the Laboratory Information System (LIS) and Hospital Information System (HIS) in Peking Union Medical College Hospital from 2014 to 2018. Total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were analyzed.

RESULTS

The serum TC [male vs. female: (4.71 ± 0.90 vs. 4.56 ± 0.85) mmol/L], TG [male vs. female: (1.71 ± 1.56 vs. 1.02 ± 0.68) mmol/L], and LDL-C [male vs. female: (3.01 ± 0.77 vs. 2.73 ± 0.74) mmol/L] levels were significantly higher in males than in females (P < 0.001); serum HDL-C [male vs. female: (1.18 ± 0.28 vs. 1.50 ± 0.34) mmol/L] was significantly lower in males (P < 0.001). In February, the TC, TG, and LDL-C levels were 8.4%, 16.3%, and 9.3% higher than the lowest levels recorded, respectively. The prevalence of dyslipidemia of the two weeks before the Spring festival was significantly lower than that of the first week after the Spring festival (43.6% (168/385) vs. 54.1% (126/233), P=0.007). Additionally, the prevalence of dyslipidemia was statistically higher in the first week after the Spring Festival than in May-January.

CONCLUSION

Higher TC, TG, and LDL-C in winter could be associated with high-fat diets during the Spring Festival. The Spring Festival was immediately followed by a higher lipid concentrations. Thus, we don't recommend lipid assessment or physical examination immediately after the holiday especially Spring festival.

Association between Physical Activity and Seasonal Variations in Metabolic and Vascular Function in Adults

This article highlights the association between physical activity (PA) and seasonal variations in metabolic and vascular function in adults. Increasing PA is an important method for preventing cardiovascular disease (CVD) and all-cause mortality by improving blood glucose, blood pressure, blood lipid profiles, body fat, insulin resistance, and vascular function, such as endothelial function. Conversely, various factors, such as seasonal climate conditions, may affect the amount of PA that individuals undertake. Changes in PA often induce seasonal variations in metabolic and vascular function; the deterioration of such functions in winter is the most prominent, and there is clear evidence of an increased risk of CVD in this season. Understanding the influence of PA on seasonal variations observed in metabolic and vascular function is necessary for the management of these physiological functions. In this article summary, few studies have proven that maintaining PA can suppress the variations, and it remains unclear what types, intensities, and durations of regular PA are effective for circumventing seasonal impact. In addition to further studies, there is a need to educate individuals about the strategies to manage PA and other aspects of their lifestyles throughout the year, particularly in winter.

Effect of maintaining supervised gym- and home-based exercises on the seasonal variations of metabolic outcomes in overweight and obese Japanese adults

Objectives

This study aimed to examine whether maintaining supervised gym- and home-based exercises for an extended time of period could decrease seasonal variations of metabolic outcomes in overweight and obese Japanese adults.

Methods

This retrospective study recruited 54 overweight and obese outpatients who started exercising in 2006–2010 and analysed their metabolic outcomes for 5 years from March 2011 to February 2016. In this group, 26 participants performed moderate-intensity aerobic exercise (MIAE) for 30–40 min/day for at least 2 days/week, supervised by physical therapists at a hospital gym (GYM) during the observation period. Conversely, 28 participants were asked to perform MIAE by themselves at or around their homes (HOME) for the same duration.

Results

The body mass index (BMI), waist circumference and homoeostasis model assessment of insulin resistance (HOMA-IR) values in winter were higher than those in other seasons in the HOME group but not in the GYM group. The annual ranges of BMI, waist circumference, fasting plasma glucose and HOMA-IR in the GYM group were smaller than those in the HOME group.

Conclusion

Maintaining supervised gym-based exercise, as opposed to home-based exercise, may decrease seasonal variations of some metabolic outcomes in overweight and obese Japanese adults.

Data mining: Seasonal fluctuations and associations between thyroid stimulating hormone and lipid profiles

OBJECTIVE

Thyroid stimulating hormone (TSH) is associated with lipid metabolism. In this study, we aimed to evaluate seasonal variations and the association between TSH and lipid profiles based on clinical big data.

METHOD

This observational, retrospective big data study enrolled a total of 20,192 individuals who visited Peking Union Medical College Hospital for routine health check-ups from 2014 to 2018. Demographic, medical history, common biochemical analytes, and thyroid related test data were obtained. A Kruskal-wallis analysis was used to compare the differences in total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) by TSH quartiles. Spearman correlation analysis was used to evaluate the association between TSH and lipid profiles as well as temperature.

RESULTS

TC and LDL did not vary significantly with TSH concentration; however, TG and HDL-C did. TSH concentration showed weak positive correlation with serum TC, TG, and HDL-C but not with LDL-C. Serum TC concentration was positively correlated with TG and LDL-C. TG was positively correlated with LDL-C but negatively correlated with HDL-C. HDL-C was negatively correlated with LDL-C. TSH and lipid profiles showed seasonal fluctuations. Monthly median TSH, TC, and LDL-C peaked in winter and dropped to a minimum in summer. The correlation coefficient (r) between the average monthly temperature and TSH, TC, TG, HDL-C, and LDL-C was -0.424 (p = 0.001), -0.539 (p < 0.001), -0.020 (p = 0.880), -0.199 (p = 0.127), and -0.442 (p < 0.001), respectively.

CONCLUSION

Seasonal variation was observed in both TSH and lipids. Apart from the seasonal variation of TC and LDL-C, our results also have clinical interpretation. It suggested that it may not reflect the real status of lipids during and immediately after the Spring festival. Thus, in order to diagnosis of hypercholesterolemia, re-testing was needed later to provide the precision diagnostic, monitoring and treatment.

Are the Levels of Lipid Parameters Associated with Biometeorological Conditions?

Lipid disorders, especially hypercholesterolemia, are one of the most thoroughly investigated cardiovascular risk factors. Their correlation with biometeorological conditions has been reported, with authors stressing seasonal increases of total cholesterol (TC) levels, mostly occurring in winter. This study aims at determining the correlation between the level of lipid parameters (LP) and meteorological conditions, analyzing seasonal variations in LP levels, and attempting to answer the following questions: do changes in LP levels result from the organism’s response to cold or heat stress, or are they secondary to seasonal dietary variations? An observational study comprised ambulatory patients from the city of Olsztyn (Poland), for whom laboratory test were performed in 2016–2018, with 106,325 records of TC, high-density lipoprotein (HDL), and triglycerides (TG). LP levels were matched with atmospheric conditions on the day when the test was conducted and expressed by the universal thermal climate index (UTCI). We demonstrated seasonal increases of TC in cold stress (in wintertime) and of TG in heat stress (summer). The analysis of LP levels in specific periods revealed the increase of TC levels after holidays (i.e., Christmas and Easter) in men by 4.56%, and the increase of TG levels in women by 13.46% in the same period. Our results suggest the secondary, diet-dependent underlying cause of the observed changes. This work contributes to the discussion concerning the impact of biometeorological factors on LP levels and may be of significance when planning population-dedicated preventive activities.